# ffplay-all(1) - man - phpman [FFPLAY-ALL(1)](https://www.chedong.com/phpMan.php/man/FFPLAY-ALL/1/markdown) [FFPLAY-ALL(1)](https://www.chedong.com/phpMan.php/man/FFPLAY-ALL/1/markdown) ## NAME ffplay - FFplay media player ## SYNOPSIS ffplay [_options_] [_input_url_] ## DESCRIPTION FFplay is a very simple and portable media player using the FFmpeg libraries and the SDL library. It is mostly used as a testbed for the various FFmpeg APIs. ## OPTIONS All the numerical options, if not specified otherwise, accept a string representing a number as input, which may be followed by one of the SI unit prefixes, for example: 'K', 'M', or 'G'. If 'i' is appended to the SI unit prefix, the complete prefix will be interpreted as a unit prefix for binary multiples, which are based on powers of 1024 instead of powers of 1000. Appending 'B' to the SI unit prefix multiplies the value by 8. This allows using, for example: 'KB', 'MiB', 'G' and 'B' as number suffixes. Options which do not take arguments are boolean options, and set the corresponding value to true. They can be set to false by prefixing the option name with "no". For example using "-nofoo" will set the boolean option with name "foo" to false. ### Stream specifiers Some options are applied per-stream, e.g. bitrate or codec. Stream specifiers are used to precisely specify which stream(s) a given option belongs to. A stream specifier is a string generally appended to the option name and separated from it by a colon. E.g. "-codec:a:1 ac3" contains the "a:1" stream specifier, which matches the second audio stream. Therefore, it would select the ac3 codec for the second audio stream. A stream specifier can match several streams, so that the option is applied to all of them. E.g. the stream specifier in "-b:a 128k" matches all audio streams. An empty stream specifier matches all streams. For example, "-codec copy" or "-codec: copy" would copy all the streams without reencoding. Possible forms of stream specifiers are: _stream_index_ Matches the stream with this index. E.g. "-threads:1 4" would set the thread count for the second stream to 4. If _stream_index_ is used as an additional stream specifier (see below), then it selects stream number _stream_index_ from the matching streams. Stream numbering is based on the order of the streams as detected by libavformat except when a program ID is also specified. In this case it is based on the ordering of the streams in the program. _stream_type_**[:**_additional_stream_specifier_**]** _stream_type_ is one of following: 'v' or 'V' for video, 'a' for audio, 's' for subtitle, 'd' for data, and 't' for attachments. 'v' matches all video streams, 'V' only matches video streams which are not attached pictures, video thumbnails or cover arts. If _additional_stream_specifier_ is used, then it matches streams which both have this type and match the _additional_stream_specifier_. Otherwise, it matches all streams of the specified type. **p:**_program_id_**[:**_additional_stream_specifier_**]** Matches streams which are in the program with the id _program_id_. If _additional_stream_specifier_ is used, then it matches streams which both are part of the program and match the _additional_stream_specifier_. **#**_stream_id_ **or** **i:**_stream_id_ Match the stream by stream id (e.g. PID in MPEG-TS container). **m:**_key_**[:**_value_**]** Matches streams with the metadata tag _key_ having the specified value. If _value_ is not given, matches streams that contain the given tag with any value. **u** Matches streams with usable configuration, the codec must be defined and the essential information such as video dimension or audio sample rate must be present. Note that in **ffmpeg**, matching by metadata will only work properly for input files. ### Generic options These options are shared amongst the ff* tools. ### -L ### -h, -?, -help, --help Show help. An optional parameter may be specified to print help about a specific item. If no argument is specified, only basic (non advanced) tool options are shown. Possible values of _arg_ are: **long** Print advanced tool options in addition to the basic tool options. **full** Print complete list of options, including shared and private options for encoders, decoders, demuxers, muxers, filters, etc. **decoder=**_decoder_name_ Print detailed information about the decoder named _decoder_name_. Use the **-decoders** option to get a list of all decoders. **encoder=**_encoder_name_ Print detailed information about the encoder named _encoder_name_. Use the **-encoders** option to get a list of all encoders. **demuxer=**_demuxer_name_ Print detailed information about the demuxer named _demuxer_name_. Use the **-formats** option to get a list of all demuxers and muxers. **muxer=**_muxer_name_ Print detailed information about the muxer named _muxer_name_. Use the **-formats** option to get a list of all muxers and demuxers. **filter=**_filter_name_ Print detailed information about the filter named _filter_name_. Use the **-filters** option to get a list of all filters. **bsf=**_bitstream_filter_name_ Print detailed information about the bitstream filter named _bitstream_filter_name_. Use the **-bsfs** option to get a list of all bitstream filters. **protocol=**_protocol_name_ Print detailed information about the protocol named _protocol_name_. Use the **-protocols** option to get a list of all protocols. ### -version Show version. ### -buildconf Show the build configuration, one option per line. ### -formats Show available formats (including devices). ### -demuxers Show available demuxers. ### -muxers Show available muxers. ### -devices Show available devices. ### -codecs Show all codecs known to libavcodec. Note that the term 'codec' is used throughout this documentation as a shortcut for what is more correctly called a media bitstream format. ### -decoders Show available decoders. ### -encoders Show all available encoders. ### -bsfs Show available bitstream filters. ### -protocols Show available protocols. ### -filters Show available libavfilter filters. ### -pix Show available pixel formats. ### -sample Show available sample formats. ### -layouts Show channel names and standard channel layouts. ### -colors Show recognized color names. ### -sources Show autodetected sources of the input device. Some devices may provide system-dependent source names that cannot be autodetected. The returned list cannot be assumed to be always complete. ffmpeg -sources pulse,server=192.168.0.4 ### -sinks Show autodetected sinks of the output device. Some devices may provide system-dependent sink names that cannot be autodetected. The returned list cannot be assumed to be always complete. ffmpeg -sinks pulse,server=192.168.0.4 ### -loglevel -v Set logging level and flags used by the library. The optional _flags_ prefix can consist of the following values: **repeat** Indicates that repeated log output should not be compressed to the first line and the "Last message repeated n times" line will be omitted. **level** Indicates that log output should add a "[level]" prefix to each message line. This can be used as an alternative to log coloring, e.g. when dumping the log to file. Flags can also be used alone by adding a '+'/'-' prefix to set/reset a single flag without affecting other _flags_ or changing _loglevel_. When setting both _flags_ and _loglevel_, a '+' separator is expected between the last _flags_ value and before _loglevel_. _loglevel_ is a string or a number containing one of the following values: **quiet,** **-8** Show nothing at all; be silent. **panic,** **0** Only show fatal errors which could lead the process to crash, such as an assertion failure. This is not currently used for anything. **fatal,** **8** Only show fatal errors. These are errors after which the process absolutely cannot continue. **error,** **16** Show all errors, including ones which can be recovered from. **warning,** **24** Show all warnings and errors. Any message related to possibly incorrect or unexpected events will be shown. **info,** **32** Show informative messages during processing. This is in addition to warnings and errors. This is the default value. **verbose,** **40** Same as "info", except more verbose. **debug,** **48** Show everything, including debugging information. **trace,** **56** For example to enable repeated log output, add the "level" prefix, and set _loglevel_ to "verbose": ffmpeg -loglevel repeat+level+verbose -i input output Another example that enables repeated log output without affecting current state of "level" prefix flag or _loglevel_: ffmpeg [...] -loglevel +repeat By default the program logs to stderr. If coloring is supported by the terminal, colors are used to mark errors and warnings. Log coloring can be disabled setting the environment variable **AV**___**LOG**___**FORCE**___**NOCOLOR**, or can be forced setting the environment variable **AV**___**LOG**___**FORCE**___**COLOR**. ### -report Dump full command line and log output to a file named "_program-YYYYMMDD-HHMMSS.log"_ in the current directory. This file can be useful for bug reports. It also implies "-loglevel debug". Setting the environment variable **FFREPORT** to any value has the same effect. If the value is a ':'-separated key=value sequence, these options will affect the report; option values must be escaped if they contain special characters or the options delimiter ':' (see the ``Quoting and escaping'' section in the ffmpeg-utils manual). The following options are recognized: **file** set the file name to use for the report; %p is expanded to the name of the program, %t is expanded to a timestamp, "%%" is expanded to a plain "%" **level** set the log verbosity level using a numerical value (see "-loglevel"). For example, to output a report to a file named _ffreport.log_ using a log level of 32 (alias for log level "info"): FFREPORT=file=ffreport.log:level=32 ffmpeg -i input output Errors in parsing the environment variable are not fatal, and will not appear in the report. ### -hide Suppress printing banner. All FFmpeg tools will normally show a copyright notice, build options and library versions. This option can be used to suppress printing this information. ### -cpuflags Allows setting and clearing cpu flags. This option is intended for testing. Do not use it unless you know what you're doing. ffmpeg -cpuflags -sse+mmx ... ffmpeg -cpuflags mmx ... ffmpeg -cpuflags 0 ... Possible flags for this option are: **x86** **mmx** **mmxext** **sse** **sse2** **sse2slow** **sse3** **sse3slow** **ssse3** **atom** **sse4.1** **sse4.2** **avx** **avx2** **xop** **fma3** **fma4** **3dnow** **3dnowext** **bmi1** **bmi2** **cmov** **ARM** **armv5te** **armv6** **armv6t2** **vfp** **vfpv3** **neon** **setend** **AArch64** **armv8** **vfp** **neon** **PowerPC** **altivec** **Specific** **Processors** **pentium2** **pentium3** **pentium4** **k6** **k62** **athlon** **athlonxp** **k8** ### -max Set the maximum size limit for allocating a block on the heap by ffmpeg's family of malloc functions. Exercise **extreme** **caution** when using this option. Don't use if you do not understand the full consequence of doing so. Default is INT_MAX. ### AVOptions These options are provided directly by the libavformat, libavdevice and libavcodec libraries. To see the list of available AVOptions, use the **-help** option. They are separated into two categories: ### generic These options can be set for any container, codec or device. Generic options are listed under AVFormatContext options for containers/devices and under AVCodecContext options for codecs. ### private These options are specific to the given container, device or codec. Private options are listed under their corresponding containers/devices/codecs. For example to write an ID3v2.3 header instead of a default ID3v2.4 to an MP3 file, use the **id3v2**___**version** private option of the MP3 muxer: ffmpeg -i input.flac -id3v2_version 3 out.mp3 All codec AVOptions are per-stream, and thus a stream specifier should be attached to them: ffmpeg -i multichannel.mxf -map 0:v:0 -map 0:a:0 -map 0:a:0 -c:a:0 ac3 -b:a:0 640k -ac:a:1 2 -c:a:1 aac -b:2 128k out.mp4 In the above example, a multichannel audio stream is mapped twice for output. The first instance is encoded with codec ac3 and bitrate 640k. The second instance is downmixed to 2 channels and encoded with codec aac. A bitrate of 128k is specified for it using absolute index of the output stream. Note: the **-nooption** syntax cannot be used for boolean AVOptions, use **-option** **0**/**-option** **1**. Note: the old undocumented way of specifying per-stream AVOptions by prepending v/a/s to the options name is now obsolete and will be removed soon. ### Main options ### -x Force displayed width. ### -y Force displayed height. ### -s Set frame size (WxH or abbreviation), needed for videos which do not contain a header with the frame size like raw YUV. This option has been deprecated in favor of private options, try -video_size. ### -fs ### -an ### -vn ### -sn ### -ss Seek to _pos_. Note that in most formats it is not possible to seek exactly, so **ffplay** will seek to the nearest seek point to _pos_. _pos_ must be a time duration specification, see **the** **Time** **duration** **section** **in** **the** [**ffmpeg-utils(1)](https://www.chedong.com/phpMan.php/man/ffmpeg-utils/1/markdown)** **manual**. ### -t Play _duration_ seconds of audio/video. _duration_ must be a time duration specification, see **the** **Time** **duration** **section** **in** **the** [**ffmpeg-utils(1)](https://www.chedong.com/phpMan.php/man/ffmpeg-utils/1/markdown)** **manual**. ### -bytes Seek by bytes. ### -seek Set custom interval, in seconds, for seeking using left/right keys. Default is 10 seconds. ### -nodisp Disable graphical display. ### -noborder Borderless window. ### -alwaysontop Window always on top. Available on: X11 with SDL >= 2.0.5, Windows SDL >= 2.0.6. ### -volume Set the startup volume. 0 means silence, 100 means no volume reduction or amplification. Negative values are treated as 0, values above 100 are treated as 100. ### -f Force format. ### -window Set window title (default is the input filename). ### -left Set the x position for the left of the window (default is a centered window). ### -top Set the y position for the top of the window (default is a centered window). ### -loop Loops movie playback times. 0 means forever. ### -showmode Set the show mode to use. Available values for _mode_ are: **0,** **video** show video **1,** **waves** show audio waves **2,** **rdft** show audio frequency band using RDFT ((Inverse) Real Discrete Fourier Transform) Default value is "video", if video is not present or cannot be played "rdft" is automatically selected. You can interactively cycle through the available show modes by pressing the key **w**. ### -vf Create the filtergraph specified by _filtergraph_ and use it to filter the video stream. _filtergraph_ is a description of the filtergraph to apply to the stream, and must have a single video input and a single video output. In the filtergraph, the input is associated to the label "in", and the output to the label "out". See the ffmpeg-filters manual for more information about the filtergraph syntax. You can specify this parameter multiple times and cycle through the specified filtergraphs along with the show modes by pressing the key **w**. ### -af _filtergraph_ is a description of the filtergraph to apply to the input audio. Use the option "-filters" to show all the available filters (including sources and sinks). ### -i Read _input_url_. ### Advanced options ### -pix Set pixel format. This option has been deprecated in favor of private options, try -pixel_format. ### -stats Print several playback statistics, in particular show the stream duration, the codec parameters, the current position in the stream and the audio/video synchronisation drift. It is shown by default, unless the log level is lower than "info". Its display can be forced by manually specifying this option. To disable it, you need to specify "-nostats". ### -fast Non-spec-compliant optimizations. ### -genpts Generate pts. ### -sync Set the master clock to audio ("type=audio"), video ("type=video") or external ("type=ext"). Default is audio. The master clock is used to control audio-video synchronization. Most media players use audio as master clock, but in some cases (streaming or high quality broadcast) it is necessary to change that. This option is mainly used for debugging purposes. ### -ast Select the desired audio stream using the given stream specifier. The stream specifiers are described in the **Stream** **specifiers** chapter. If this option is not specified, the "best" audio stream is selected in the program of the already selected video stream. ### -vst Select the desired video stream using the given stream specifier. The stream specifiers are described in the **Stream** **specifiers** chapter. If this option is not specified, the "best" video stream is selected. ### -sst Select the desired subtitle stream using the given stream specifier. The stream specifiers are described in the **Stream** **specifiers** chapter. If this option is not specified, the "best" subtitle stream is selected in the program of the already selected video or audio stream. ### -autoexit Exit when video is done playing. ### -exitonkeydown Exit if any key is pressed. ### -exitonmousedown Exit if any mouse button is pressed. ### -codec: Force a specific decoder implementation for the stream identified by _media_specifier_, which can assume the values "a" (audio), "v" (video), and "s" subtitle. ### -acodec Force a specific audio decoder. ### -vcodec Force a specific video decoder. ### -scodec Force a specific subtitle decoder. ### -autorotate Automatically rotate the video according to file metadata. Enabled by default, use **-noautorotate** to disable it. ### -framedrop Drop video frames if video is out of sync. Enabled by default if the master clock is not set to video. Use this option to enable frame dropping for all master clock sources, use **-noframedrop** to disable it. ### -infbuf Do not limit the input buffer size, read as much data as possible from the input as soon as possible. Enabled by default for realtime streams, where data may be dropped if not read in time. Use this option to enable infinite buffers for all inputs, use **-noinfbuf** to disable it. ### -filter Defines how many threads are used to process a filter pipeline. Each pipeline will produce a thread pool with this many threads available for parallel processing. The default is 0 which means that the thread count will be determined by the number of available CPUs. ### While playing ### q, ESC Quit. **f** Toggle full screen. ### p, SPC Pause. **m** Toggle mute. ### 9, 0 Decrease and increase volume respectively. **/,** ***** Decrease and increase volume respectively. **a** Cycle audio channel in the current program. **v** Cycle video channel. **t** Cycle subtitle channel in the current program. **c** Cycle program. **w** Cycle video filters or show modes. **s** Step to the next frame. Pause if the stream is not already paused, step to the next video frame, and pause. ### left/right Seek backward/forward 10 seconds. ### down/up Seek backward/forward 1 minute. ### page down/page up Seek to the previous/next chapter. or if there are no chapters Seek backward/forward 10 minutes. ### right mouse click Seek to percentage in file corresponding to fraction of width. ### left mouse double-click Toggle full screen. ## SYNTAX This section documents the syntax and formats employed by the FFmpeg libraries and tools. ### Quoting and escaping FFmpeg adopts the following quoting and escaping mechanism, unless explicitly specified. The following rules are applied: • **'** and **\** are special characters (respectively used for quoting and escaping). In addition to them, there might be other special characters depending on the specific syntax where the escaping and quoting are employed. • A special character is escaped by prefixing it with a **\**. • All characters enclosed between **''** are included literally in the parsed string. The quote character **'** itself cannot be quoted, so you may need to close the quote and escape it. • Leading and trailing whitespaces, unless escaped or quoted, are removed from the parsed string. Note that you may need to add a second level of escaping when using the command line or a script, which depends on the syntax of the adopted shell language. The function "av_get_token" defined in _libavutil/avstring.h_ can be used to parse a token quoted or escaped according to the rules defined above. The tool _tools/ffescape_ in the FFmpeg source tree can be used to automatically quote or escape a string in a script. _Examples_ • Escape the string "Crime d'Amour" containing the "'" special character: Crime d\'Amour • The string above contains a quote, so the "'" needs to be escaped when quoting it: 'Crime d'\''Amour' • Include leading or trailing whitespaces using quoting: ' this string starts and ends with whitespaces ' • Escaping and quoting can be mixed together: ' The string '\'string\'' is a string ' • To include a literal **\** you can use either escaping or quoting: 'c:\foo' can be written as c:\\foo ### Date The accepted syntax is: [(YYYY-MM-DD|YYYYMMDD)[T|t| ]]((HH:MM:SS[.m...]]])|(HHMMSS[.m...]]]))[Z] now If the value is "now" it takes the current time. Time is local time unless Z is appended, in which case it is interpreted as UTC. If the year-month-day part is not specified it takes the current year-month-day. ### Time duration There are two accepted syntaxes for expressing time duration. [-][:]:[....] _HH_ expresses the number of hours, _MM_ the number of minutes for a maximum of 2 digits, and _SS_ the number of seconds for a maximum of 2 digits. The _m_ at the end expresses decimal value for _SS_. _or_ [-]+[....][s|ms|us] _S_ expresses the number of seconds, with the optional decimal part _m_. The optional literal suffixes **s**, **ms** or **us** indicate to interpret the value as seconds, milliseconds or microseconds, respectively. In both expressions, the optional **-** indicates negative duration. _Examples_ The following examples are all valid time duration: **55** 55 seconds **0.2** 0.2 seconds ### 200ms 200 milliseconds, that's 0.2s ### 200000us 200000 microseconds, that's 0.2s ### 12:03:45 12 hours, 03 minutes and 45 seconds ### 23.189 23.189 seconds ### Video size Specify the size of the sourced video, it may be a string of the form _width_x_height_, or the name of a size abbreviation. The following abbreviations are recognized: ### ntsc 720x480 **pal** 720x576 ### qntsc 352x240 ### qpal 352x288 ### sntsc 640x480 ### spal 768x576 ### film 352x240 ### ntsc-film 352x240 ### sqcif 128x96 ### qcif 176x144 **cif** 352x288 ### 4cif 704x576 ### 16cif 1408x1152 ### qqvga 160x120 ### qvga 320x240 **vga** 640x480 ### svga 800x600 **xga** 1024x768 ### uxga 1600x1200 ### qxga 2048x1536 ### sxga 1280x1024 ### qsxga 2560x2048 ### hsxga 5120x4096 ### wvga 852x480 ### wxga 1366x768 ### wsxga 1600x1024 ### wuxga 1920x1200 ### woxga 2560x1600 ### wqsxga 3200x2048 ### wquxga 3840x2400 ### whsxga 6400x4096 ### whuxga 7680x4800 **cga** 320x200 **ega** 640x350 ### hd480 852x480 ### hd720 1280x720 ### hd1080 1920x1080 **2k** 2048x1080 ### 2kflat 1998x1080 ### 2kscope 2048x858 **4k** 4096x2160 ### 4kflat 3996x2160 ### 4kscope 4096x1716 **nhd** 640x360 ### hqvga 240x160 ### wqvga 400x240 ### fwqvga 432x240 ### hvga 480x320 **qhd** 960x540 ### 2kdci 2048x1080 ### 4kdci 4096x2160 ### uhd2160 3840x2160 ### uhd4320 7680x4320 ### Video rate Specify the frame rate of a video, expressed as the number of frames generated per second. It has to be a string in the format _frame_rate_num_/_frame_rate_den_, an integer number, a float number or a valid video frame rate abbreviation. The following abbreviations are recognized: ### ntsc 30000/1001 **pal** 25/1 ### qntsc 30000/1001 ### qpal 25/1 ### sntsc 30000/1001 ### spal 25/1 ### film 24/1 ### ntsc-film 24000/1001 ### Ratio A ratio can be expressed as an expression, or in the form _numerator_:_denominator_. Note that a ratio with infinite (1/0) or negative value is considered valid, so you should check on the returned value if you want to exclude those values. The undefined value can be expressed using the "0:0" string. ### Color It can be the name of a color as defined below (case insensitive match) or a "[0x|#]RRGGBB[AA]" sequence, possibly followed by @ and a string representing the alpha component. The alpha component may be a string composed by "0x" followed by an hexadecimal number or a decimal number between 0.0 and 1.0, which represents the opacity value (**0x00** or **0.0** means completely transparent, **0xff** or **1.0** completely opaque). If the alpha component is not specified then **0xff** is assumed. The string **random** will result in a random color. The following names of colors are recognized: ### AliceBlue 0xF0F8FF ### AntiqueWhite 0xFAEBD7 ### Aqua 0x00FFFF ### Aquamarine 0x7FFFD4 ### Azure 0xF0FFFF ### Beige 0xF5F5DC ### Bisque 0xFFE4C4 ### Black 0x000000 ### BlanchedAlmond 0xFFEBCD ### Blue 0x0000FF ### BlueViolet 0x8A2BE2 ### Brown 0xA52A2A ### BurlyWood 0xDEB887 ### CadetBlue 0x5F9EA0 ### Chartreuse 0x7FFF00 ### Chocolate 0xD2691E ### Coral 0xFF7F50 ### CornflowerBlue 0x6495ED ### Cornsilk 0xFFF8DC ### Crimson 0xDC143C ### Cyan 0x00FFFF ### DarkBlue 0x00008B ### DarkCyan 0x008B8B ### DarkGoldenRod 0xB8860B ### DarkGray 0xA9A9A9 ### DarkGreen 0x006400 ### DarkKhaki 0xBDB76B ### DarkMagenta 0x8B008B ### DarkOliveGreen 0x556B2F ### Darkorange 0xFF8C00 ### DarkOrchid 0x9932CC ### DarkRed 0x8B0000 ### DarkSalmon 0xE9967A ### DarkSeaGreen 0x8FBC8F ### DarkSlateBlue 0x483D8B ### DarkSlateGray 0x2F4F4F ### DarkTurquoise 0x00CED1 ### DarkViolet 0x9400D3 ### DeepPink 0xFF1493 ### DeepSkyBlue 0x00BFFF ### DimGray 0x696969 ### DodgerBlue 0x1E90FF ### FireBrick 0xB22222 ### FloralWhite 0xFFFAF0 ### ForestGreen 0x228B22 ### Fuchsia 0xFF00FF ### Gainsboro 0xDCDCDC ### GhostWhite 0xF8F8FF ### Gold 0xFFD700 ### GoldenRod 0xDAA520 ### Gray 0x808080 ### Green 0x008000 ### GreenYellow 0xADFF2F ### HoneyDew 0xF0FFF0 ### HotPink 0xFF69B4 ### IndianRed 0xCD5C5C ### Indigo 0x4B0082 ### Ivory 0xFFFFF0 ### Khaki 0xF0E68C ### Lavender 0xE6E6FA ### LavenderBlush 0xFFF0F5 ### LawnGreen 0x7CFC00 ### LemonChiffon 0xFFFACD ### LightBlue 0xADD8E6 ### LightCoral 0xF08080 ### LightCyan 0xE0FFFF ### LightGoldenRodYellow 0xFAFAD2 ### LightGreen 0x90EE90 ### LightGrey 0xD3D3D3 ### LightPink 0xFFB6C1 ### LightSalmon 0xFFA07A ### LightSeaGreen 0x20B2AA ### LightSkyBlue 0x87CEFA ### LightSlateGray 0x778899 ### LightSteelBlue 0xB0C4DE ### LightYellow 0xFFFFE0 ### Lime 0x00FF00 ### LimeGreen 0x32CD32 ### Linen 0xFAF0E6 ### Magenta 0xFF00FF ### Maroon 0x800000 ### MediumAquaMarine 0x66CDAA ### MediumBlue 0x0000CD ### MediumOrchid 0xBA55D3 ### MediumPurple 0x9370D8 ### MediumSeaGreen 0x3CB371 ### MediumSlateBlue 0x7B68EE ### MediumSpringGreen 0x00FA9A ### MediumTurquoise 0x48D1CC ### MediumVioletRed 0xC71585 ### MidnightBlue 0x191970 ### MintCream 0xF5FFFA ### MistyRose 0xFFE4E1 ### Moccasin 0xFFE4B5 ### NavajoWhite 0xFFDEAD ### Navy 0x000080 ### OldLace 0xFDF5E6 ### Olive 0x808000 ### OliveDrab 0x6B8E23 ### Orange 0xFFA500 ### OrangeRed 0xFF4500 ### Orchid 0xDA70D6 ### PaleGoldenRod 0xEEE8AA ### PaleGreen 0x98FB98 ### PaleTurquoise 0xAFEEEE ### PaleVioletRed 0xD87093 ### PapayaWhip 0xFFEFD5 ### PeachPuff 0xFFDAB9 ### Peru 0xCD853F ### Pink 0xFFC0CB ### Plum 0xDDA0DD ### PowderBlue 0xB0E0E6 ### Purple 0x800080 **Red** 0xFF0000 ### RosyBrown 0xBC8F8F ### RoyalBlue 0x4169E1 ### SaddleBrown 0x8B4513 ### Salmon 0xFA8072 ### SandyBrown 0xF4A460 ### SeaGreen 0x2E8B57 ### SeaShell 0xFFF5EE ### Sienna 0xA0522D ### Silver 0xC0C0C0 ### SkyBlue 0x87CEEB ### SlateBlue 0x6A5ACD ### SlateGray 0x708090 ### Snow 0xFFFAFA ### SpringGreen 0x00FF7F ### SteelBlue 0x4682B4 **Tan** 0xD2B48C ### Teal 0x008080 ### Thistle 0xD8BFD8 ### Tomato 0xFF6347 ### Turquoise 0x40E0D0 ### Violet 0xEE82EE ### Wheat 0xF5DEB3 ### White 0xFFFFFF ### WhiteSmoke 0xF5F5F5 ### Yellow 0xFFFF00 ### YellowGreen 0x9ACD32 ### Channel Layout A channel layout specifies the spatial disposition of the channels in a multi-channel audio stream. To specify a channel layout, FFmpeg makes use of a special syntax. Individual channels are identified by an id, as given by the table below: **FL** front left **FR** front right **FC** front center **LFE** low frequency **BL** back left **BR** back right **FLC** front left-of-center **FRC** front right-of-center **BC** back center **SL** side left **SR** side right **TC** top center **TFL** top front left **TFC** top front center **TFR** top front right **TBL** top back left **TBC** top back center **TBR** top back right **DL** downmix left **DR** downmix right **WL** wide left **WR** wide right **SDL** surround direct left **SDR** surround direct right **LFE2** low frequency 2 Standard channel layout compositions can be specified by using the following identifiers: ### mono FC ### stereo FL+FR **2.1** FL+FR+LFE **3.0** FL+FR+FC ### 3.0(back) FL+FR+BC **4.0** FL+FR+FC+BC ### quad FL+FR+BL+BR ### quad(side) FL+FR+SL+SR **3.1** FL+FR+FC+LFE **5.0** FL+FR+FC+BL+BR ### 5.0(side) FL+FR+FC+SL+SR **4.1** FL+FR+FC+LFE+BC **5.1** FL+FR+FC+LFE+BL+BR ### 5.1(side) FL+FR+FC+LFE+SL+SR **6.0** FL+FR+FC+BC+SL+SR ### 6.0(front) FL+FR+FLC+FRC+SL+SR ### hexagonal FL+FR+FC+BL+BR+BC **6.1** FL+FR+FC+LFE+BC+SL+SR **6.1** FL+FR+FC+LFE+BL+BR+BC ### 6.1(front) FL+FR+LFE+FLC+FRC+SL+SR **7.0** FL+FR+FC+BL+BR+SL+SR ### 7.0(front) FL+FR+FC+FLC+FRC+SL+SR **7.1** FL+FR+FC+LFE+BL+BR+SL+SR ### 7.1(wide) FL+FR+FC+LFE+BL+BR+FLC+FRC ### 7.1(wide-side) FL+FR+FC+LFE+FLC+FRC+SL+SR ### octagonal FL+FR+FC+BL+BR+BC+SL+SR ### hexadecagonal FL+FR+FC+BL+BR+BC+SL+SR+WL+WR+TBL+TBR+TBC+TFC+TFL+TFR ### downmix DL+DR A custom channel layout can be specified as a sequence of terms, separated by '+' or '|'. Each term can be: • the name of a standard channel layout (e.g. **mono**, **stereo**, **4.0**, **quad**, **5.0**, etc.) • the name of a single channel (e.g. **FL**, **FR**, **FC**, **LFE**, etc.) • a number of channels, in decimal, followed by 'c', yielding the default channel layout for that number of channels (see the function "av_get_default_channel_layout"). Note that not all channel counts have a default layout. • a number of channels, in decimal, followed by 'C', yielding an unknown channel layout with the specified number of channels. Note that not all channel layout specification strings support unknown channel layouts. • a channel layout mask, in hexadecimal starting with "0x" (see the "AV_CH_*" macros in _libavutil/channel_layout.h_. Before libavutil version 53 the trailing character "c" to specify a number of channels was optional, but now it is required, while a channel layout mask can also be specified as a decimal number (if and only if not followed by "c" or "C"). See also the function "av_get_channel_layout" defined in _libavutil/channel_layout.h_. ## EXPRESSION EVALUATION When evaluating an arithmetic expression, FFmpeg uses an internal formula evaluator, implemented through the _libavutil/eval.h_ interface. An expression may contain unary, binary operators, constants, and functions. Two expressions _expr1_ and _expr2_ can be combined to form another expression "_expr1_;_expr2_". _expr1_ and _expr2_ are evaluated in turn, and the new expression evaluates to the value of _expr2_. The following binary operators are available: "+", "-", "*", "/", "^". The following unary operators are available: "+", "-". The following functions are available: ### abs(x) Compute absolute value of _x_. ### acos(x) Compute arccosine of _x_. ### asin(x) Compute arcsine of _x_. ### atan(x) Compute arctangent of _x_. ### atan2(x, y) Compute principal value of the arc tangent of _y_/_x_. ### between(x, min, max) Return 1 if _x_ is greater than or equal to _min_ and lesser than or equal to _max_, 0 otherwise. ### bitand(x, y) ### bitor(x, y) Compute bitwise and/or operation on _x_ and _y_. The results of the evaluation of _x_ and _y_ are converted to integers before executing the bitwise operation. Note that both the conversion to integer and the conversion back to floating point can lose precision. Beware of unexpected results for large numbers (usually 2^53 and larger). ### ceil(expr) Round the value of expression _expr_ upwards to the nearest integer. For example, "ceil(1.5)" is "2.0". ### clip(x, min, max) Return the value of _x_ clipped between _min_ and _max_. ### cos(x) Compute cosine of _x_. ### cosh(x) Compute hyperbolic cosine of _x_. ### eq(x, y) Return 1 if _x_ and _y_ are equivalent, 0 otherwise. ### exp(x) Compute exponential of _x_ (with base "e", the Euler's number). ### floor(expr) Round the value of expression _expr_ downwards to the nearest integer. For example, "floor(-1.5)" is "-2.0". ### gauss(x) Compute Gauss function of _x_, corresponding to "exp(-x*x/2) / sqrt(2*PI)". ### gcd(x, y) Return the greatest common divisor of _x_ and _y_. If both _x_ and _y_ are 0 or either or both are less than zero then behavior is undefined. ### gt(x, y) Return 1 if _x_ is greater than _y_, 0 otherwise. ### gte(x, y) Return 1 if _x_ is greater than or equal to _y_, 0 otherwise. ### hypot(x, y) This function is similar to the C function with the same name; it returns "sqrt(_x_*_x_ + _y_*_y_)", the length of the hypotenuse of a right triangle with sides of length _x_ and _y_, or the distance of the point (_x_, _y_) from the origin. ### if(x, y) Evaluate _x_, and if the result is non-zero return the result of the evaluation of _y_, return 0 otherwise. ### if(x, y, z) Evaluate _x_, and if the result is non-zero return the evaluation result of _y_, otherwise the evaluation result of _z_. ### ifnot(x, y) Evaluate _x_, and if the result is zero return the result of the evaluation of _y_, return 0 otherwise. ### ifnot(x, y, z) Evaluate _x_, and if the result is zero return the evaluation result of _y_, otherwise the evaluation result of _z_. ### isinf(x) Return 1.0 if _x_ is +/-INFINITY, 0.0 otherwise. ### isnan(x) Return 1.0 if _x_ is NAN, 0.0 otherwise. ### ld(var) Load the value of the internal variable with number _var_, which was previously stored with st(_var_, _expr_). The function returns the loaded value. ### lerp(x, y, z) Return linear interpolation between _x_ and _y_ by amount of _z_. ### log(x) Compute natural logarithm of _x_. ### lt(x, y) Return 1 if _x_ is lesser than _y_, 0 otherwise. ### lte(x, y) Return 1 if _x_ is lesser than or equal to _y_, 0 otherwise. ### max(x, y) Return the maximum between _x_ and _y_. ### min(x, y) Return the minimum between _x_ and _y_. ### mod(x, y) Compute the remainder of division of _x_ by _y_. ### not(expr) Return 1.0 if _expr_ is zero, 0.0 otherwise. ### pow(x, y) Compute the power of _x_ elevated _y_, it is equivalent to "(_x_)^(_y_)". ### print(t) ### print(t, l) Print the value of expression _t_ with loglevel _l_. If _l_ is not specified then a default log level is used. Returns the value of the expression printed. Prints t with loglevel l ### random(x) Return a pseudo random value between 0.0 and 1.0. _x_ is the index of the internal variable which will be used to save the seed/state. ### root(expr, max) Find an input value for which the function represented by _expr_ with argument [_l_l_d_d_(0)](https://www.chedong.com/phpMan.php/man/lldd/0/markdown)_ is 0 in the interval 0.._max_. The expression in _expr_ must denote a continuous function or the result is undefined. [_l_l_d_d_(0)](https://www.chedong.com/phpMan.php/man/lldd/0/markdown)_ is used to represent the function input value, which means that the given expression will be evaluated multiple times with various input values that the expression can access through [ld(0)](https://www.chedong.com/phpMan.php/man/ld/0/markdown). When the expression evaluates to 0 then the corresponding input value will be returned. ### round(expr) Round the value of expression _expr_ to the nearest integer. For example, "round(1.5)" is "2.0". ### sgn(x) Compute sign of _x_. ### sin(x) Compute sine of _x_. ### sinh(x) Compute hyperbolic sine of _x_. ### sqrt(expr) Compute the square root of _expr_. This is equivalent to "(_expr_)^.5". ### squish(x) Compute expression "1/(1 + exp(4*x))". ### st(var, expr) Store the value of the expression _expr_ in an internal variable. _var_ specifies the number of the variable where to store the value, and it is a value ranging from 0 to 9. The function returns the value stored in the internal variable. Note, Variables are currently not shared between expressions. ### tan(x) Compute tangent of _x_. ### tanh(x) Compute hyperbolic tangent of _x_. ### taylor(expr, x) ### taylor(expr, x, id) Evaluate a Taylor series at _x_, given an expression representing the "ld(id)"-th derivative of a function at 0. When the series does not converge the result is undefined. _ld(id)_ is used to represent the derivative order in _expr_, which means that the given expression will be evaluated multiple times with various input values that the expression can access through "ld(id)". If _id_ is not specified then 0 is assumed. Note, when you have the derivatives at y instead of 0, "taylor(expr, x-y)" can be used. ### [time(0)](https://www.chedong.com/phpMan.php/man/time/0/markdown) Return the current (wallclock) time in seconds. ### trunc(expr) Round the value of expression _expr_ towards zero to the nearest integer. For example, "trunc(-1.5)" is "-1.0". ### while(cond, expr) Evaluate expression _expr_ while the expression _cond_ is non-zero, and returns the value of the last _expr_ evaluation, or NAN if _cond_ was always false. The following constants are available: **PI** area of the unit disc, approximately 3.14 **E** [**exp**(1)](https://www.chedong.com/phpMan.php/man/exp/1/markdown) (Euler's number), approximately 2.718 **PHI** golden ratio (1+[**sqrt**(5)](https://www.chedong.com/phpMan.php/man/sqrt/5/markdown))/2, approximately 1.618 Assuming that an expression is considered "true" if it has a non-zero value, note that: "*" works like AND "+" works like OR For example the construct: if (A AND B) then C is equivalent to: if(A*B, C) In your C code, you can extend the list of unary and binary functions, and define recognized constants, so that they are available for your expressions. The evaluator also recognizes the International System unit prefixes. If 'i' is appended after the prefix, binary prefixes are used, which are based on powers of 1024 instead of powers of 1000. The 'B' postfix multiplies the value by 8, and can be appended after a unit prefix or used alone. This allows using for example 'KB', 'MiB', 'G' and 'B' as number postfix. The list of available International System prefixes follows, with indication of the corresponding powers of 10 and of 2. **y** 10^-24 / 2^-80 **z** 10^-21 / 2^-70 **a** 10^-18 / 2^-60 **f** 10^-15 / 2^-50 **p** 10^-12 / 2^-40 **n** 10^-9 / 2^-30 **u** 10^-6 / 2^-20 **m** 10^-3 / 2^-10 **c** 10^-2 **d** 10^-1 **h** 10^2 **k** 10^3 / 2^10 **K** 10^3 / 2^10 **M** 10^6 / 2^20 **G** 10^9 / 2^30 **T** 10^12 / 2^40 **P** 10^15 / 2^40 **E** 10^18 / 2^50 **Z** 10^21 / 2^60 **Y** 10^24 / 2^70 ## CODEC OPTIONS libavcodec provides some generic global options, which can be set on all the encoders and decoders. In addition each codec may support so-called private options, which are specific for a given codec. Sometimes, a global option may only affect a specific kind of codec, and may be nonsensical or ignored by another, so you need to be aware of the meaning of the specified options. Also some options are meant only for decoding or encoding. Options may be set by specifying -_option_ _value_ in the FFmpeg tools, or by setting the value explicitly in the "AVCodecContext" options or using the _libavutil/opt.h_ API for programmatic use. The list of supported options follow: **b** _integer_ **(**_encoding,audio,video_**)** Set bitrate in bits/s. Default value is 200K. **ab** _integer_ **(**_encoding,audio_**)** Set audio bitrate (in bits/s). Default value is 128K. **bt** _integer_ **(**_encoding,video_**)** Set video bitrate tolerance (in bits/s). In 1-pass mode, bitrate tolerance specifies how far ratecontrol is willing to deviate from the target average bitrate value. This is not related to min/max bitrate. Lowering tolerance too much has an adverse effect on quality. **flags** _flags_ **(**_decoding/encoding,audio,video,subtitles_**)** Set generic flags. Possible values: **mv4** Use four motion vector by macroblock (mpeg4). **qpel** Use 1/4 pel motion compensation. **loop** Use loop filter. **qscale** Use fixed qscale. **pass1** Use internal 2pass ratecontrol in first pass mode. **pass2** Use internal 2pass ratecontrol in second pass mode. **gray** Only decode/encode grayscale. **psnr** Set error[?] variables during encoding. **truncated** Input bitstream might be randomly truncated. **drop**___**changed** Don't output frames whose parameters differ from first decoded frame in stream. Error AVERROR_INPUT_CHANGED is returned when a frame is dropped. **ildct** Use interlaced DCT. **low**___**delay** Force low delay. **global**___**header** Place global headers in extradata instead of every keyframe. **bitexact** Only write platform-, build- and time-independent data. (except (I)DCT). This ensures that file and data checksums are reproducible and match between platforms. Its primary use is for regression testing. **aic** Apply H263 advanced intra coding / mpeg4 ac prediction. **ilme** Apply interlaced motion estimation. **cgop** Use closed gop. **output**___**corrupt** Output even potentially corrupted frames. **time**___**base** _rational_ _number_ Set codec time base. It is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented. For fixed-fps content, timebase should be "1 / frame_rate" and timestamp increments should be identically 1. **g** _integer_ **(**_encoding,video_**)** Set the group of picture (GOP) size. Default value is 12. **ar** _integer_ **(**_decoding/encoding,audio_**)** Set audio sampling rate (in Hz). **ac** _integer_ **(**_decoding/encoding,audio_**)** Set number of audio channels. **cutoff** _integer_ **(**_encoding,audio_**)** Set cutoff bandwidth. (Supported only by selected encoders, see their respective documentation sections.) **frame**___**size** _integer_ **(**_encoding,audio_**)** Set audio frame size. Each submitted frame except the last must contain exactly frame_size samples per channel. May be 0 when the codec has CODEC_CAP_VARIABLE_FRAME_SIZE set, in that case the frame size is not restricted. It is set by some decoders to indicate constant frame size. **frame**___**number** _integer_ Set the frame number. **delay** _integer_ **qcomp** _float_ **(**_encoding,video_**)** Set video quantizer scale compression (VBR). It is used as a constant in the ratecontrol equation. Recommended range for default rc_eq: 0.0-1.0. **qblur** _float_ **(**_encoding,video_**)** Set video quantizer scale blur (VBR). **qmin** _integer_ **(**_encoding,video_**)** Set min video quantizer scale (VBR). Must be included between -1 and 69, default value is 2. **qmax** _integer_ **(**_encoding,video_**)** Set max video quantizer scale (VBR). Must be included between -1 and 1024, default value is 31. **qdiff** _integer_ **(**_encoding,video_**)** Set max difference between the quantizer scale (VBR). **bf** _integer_ **(**_encoding,video_**)** Set max number of B frames between non-B-frames. Must be an integer between -1 and 16. 0 means that B-frames are disabled. If a value of -1 is used, it will choose an automatic value depending on the encoder. Default value is 0. **b**___**qfactor** _float_ **(**_encoding,video_**)** Set qp factor between P and B frames. **b**___**strategy** _integer_ **(**_encoding,video_**)** Set strategy to choose between I/P/B-frames. **ps** _integer_ **(**_encoding,video_**)** Set RTP payload size in bytes. **mv**___**bits** _integer_ **header**___**bits** _integer_ **i**___**tex**___**bits** _integer_ **p**___**tex**___**bits** _integer_ **i**___**count** _integer_ **p**___**count** _integer_ **skip**___**count** _integer_ **misc**___**bits** _integer_ **frame**___**bits** _integer_ **codec**___**tag** _integer_ **bug** _flags_ **(**_decoding,video_**)** Workaround not auto detected encoder bugs. Possible values: **autodetect** **xvid**___**ilace** Xvid interlacing bug (autodetected if fourcc==XVIX) **ump4** (autodetected if fourcc==UMP4) **no**___**padding** padding bug (autodetected) **amv** **qpel**___**chroma** **std**___**qpel** old standard qpel (autodetected per fourcc/version) **qpel**___**chroma2** **direct**___**blocksize** direct-qpel-blocksize bug (autodetected per fourcc/version) **edge** edge padding bug (autodetected per fourcc/version) **hpel**___**chroma** **dc**___**clip** **ms** Workaround various bugs in microsoft broken decoders. **trunc** trancated frames **strict** _integer_ **(**_decoding/encoding,audio,video_**)** Specify how strictly to follow the standards. Possible values: **very** strictly conform to an older more strict version of the spec or reference software **strict** strictly conform to all the things in the spec no matter what consequences **normal** **unofficial** allow unofficial extensions **experimental** allow non standardized experimental things, experimental (unfinished/work in progress/not well tested) decoders and encoders. Note: experimental decoders can pose a security risk, do not use this for decoding untrusted input. **b**___**qoffset** _float_ **(**_encoding,video_**)** Set QP offset between P and B frames. **err**___**detect** _flags_ **(**_decoding,audio,video_**)** Set error detection flags. Possible values: **crccheck** verify embedded CRCs **bitstream** detect bitstream specification deviations **buffer** detect improper bitstream length **explode** abort decoding on minor error detection **ignore**___**err** ignore decoding errors, and continue decoding. This is useful if you want to analyze the content of a video and thus want everything to be decoded no matter what. This option will not result in a video that is pleasing to watch in case of errors. **careful** consider things that violate the spec and have not been seen in the wild as errors **compliant** consider all spec non compliancies as errors **aggressive** consider things that a sane encoder should not do as an error **has**___**b**___**frames** _integer_ **block**___**align** _integer_ **mpeg**___**quant** _integer_ **(**_encoding,video_**)** Use MPEG quantizers instead of H.263. **rc**___**override**___**count** _integer_ **maxrate** _integer_ **(**_encoding,audio,video_**)** Set max bitrate tolerance (in bits/s). Requires bufsize to be set. **minrate** _integer_ **(**_encoding,audio,video_**)** Set min bitrate tolerance (in bits/s). Most useful in setting up a CBR encode. It is of little use elsewise. **bufsize** _integer_ **(**_encoding,audio,video_**)** Set ratecontrol buffer size (in bits). **i**___**qfactor** _float_ **(**_encoding,video_**)** Set QP factor between P and I frames. **i**___**qoffset** _float_ **(**_encoding,video_**)** Set QP offset between P and I frames. **dct** _integer_ **(**_encoding,video_**)** Set DCT algorithm. Possible values: **auto** autoselect a good one (default) **fastint** fast integer **int** accurate integer **mmx** **altivec** **faan** floating point AAN DCT **lumi**___**mask** _float_ **(**_encoding,video_**)** Compress bright areas stronger than medium ones. **tcplx**___**mask** _float_ **(**_encoding,video_**)** Set temporal complexity masking. **scplx**___**mask** _float_ **(**_encoding,video_**)** Set spatial complexity masking. **p**___**mask** _float_ **(**_encoding,video_**)** Set inter masking. **dark**___**mask** _float_ **(**_encoding,video_**)** Compress dark areas stronger than medium ones. **idct** _integer_ **(**_decoding/encoding,video_**)** Select IDCT implementation. Possible values: **auto** **int** **simple** **simplemmx** **simpleauto** Automatically pick a IDCT compatible with the simple one **arm** **altivec** **sh4** **simplearm** **simplearmv5te** **simplearmv6** **simpleneon** **xvid** **faani** floating point AAN IDCT **slice**___**count** _integer_ **ec** _flags_ **(**_decoding,video_**)** Set error concealment strategy. Possible values: **guess**___**mvs** iterative motion vector (MV) search (slow) **deblock** use strong deblock filter for damaged MBs **favor**___**inter** favor predicting from the previous frame instead of the current **bits**___**per**___**coded**___**sample** _integer_ **pred** _integer_ **(**_encoding,video_**)** Set prediction method. Possible values: **left** **plane** **median** **aspect** _rational_ _number_ **(**_encoding,video_**)** Set sample aspect ratio. **sar** _rational_ _number_ **(**_encoding,video_**)** Set sample aspect ratio. Alias to _aspect_. **debug** _flags_ **(**_decoding/encoding,audio,video,subtitles_**)** Print specific debug info. Possible values: **pict** picture info **rc** rate control **bitstream** **mb**___**type** macroblock (MB) type **qp** per-block quantization parameter (QP) **dct**___**coeff** **green**___**metadata** display complexity metadata for the upcoming frame, GoP or for a given duration. **skip** **startcode** **er** error recognition **mmco** memory management control operations (H.264) **bugs** **buffers** picture buffer allocations **thread**___**ops** threading operations **nomc** skip motion compensation **cmp** _integer_ **(**_encoding,video_**)** Set full pel me compare function. Possible values: **sad** sum of absolute differences, fast (default) **sse** sum of squared errors **satd** sum of absolute Hadamard transformed differences **dct** sum of absolute DCT transformed differences **psnr** sum of squared quantization errors (avoid, low quality) **bit** number of bits needed for the block **rd** rate distortion optimal, slow **zero** 0 **vsad** sum of absolute vertical differences **vsse** sum of squared vertical differences **nsse** noise preserving sum of squared differences **w53** 5/3 wavelet, only used in snow **w97** 9/7 wavelet, only used in snow **dctmax** **chroma** **subcmp** _integer_ **(**_encoding,video_**)** Set sub pel me compare function. Possible values: **sad** sum of absolute differences, fast (default) **sse** sum of squared errors **satd** sum of absolute Hadamard transformed differences **dct** sum of absolute DCT transformed differences **psnr** sum of squared quantization errors (avoid, low quality) **bit** number of bits needed for the block **rd** rate distortion optimal, slow **zero** 0 **vsad** sum of absolute vertical differences **vsse** sum of squared vertical differences **nsse** noise preserving sum of squared differences **w53** 5/3 wavelet, only used in snow **w97** 9/7 wavelet, only used in snow **dctmax** **chroma** **mbcmp** _integer_ **(**_encoding,video_**)** Set macroblock compare function. Possible values: **sad** sum of absolute differences, fast (default) **sse** sum of squared errors **satd** sum of absolute Hadamard transformed differences **dct** sum of absolute DCT transformed differences **psnr** sum of squared quantization errors (avoid, low quality) **bit** number of bits needed for the block **rd** rate distortion optimal, slow **zero** 0 **vsad** sum of absolute vertical differences **vsse** sum of squared vertical differences **nsse** noise preserving sum of squared differences **w53** 5/3 wavelet, only used in snow **w97** 9/7 wavelet, only used in snow **dctmax** **chroma** **ildctcmp** _integer_ **(**_encoding,video_**)** Set interlaced dct compare function. Possible values: **sad** sum of absolute differences, fast (default) **sse** sum of squared errors **satd** sum of absolute Hadamard transformed differences **dct** sum of absolute DCT transformed differences **psnr** sum of squared quantization errors (avoid, low quality) **bit** number of bits needed for the block **rd** rate distortion optimal, slow **zero** 0 **vsad** sum of absolute vertical differences **vsse** sum of squared vertical differences **nsse** noise preserving sum of squared differences **w53** 5/3 wavelet, only used in snow **w97** 9/7 wavelet, only used in snow **dctmax** **chroma** **dia**___**size** _integer_ **(**_encoding,video_**)** Set diamond type & size for motion estimation. **(1024,** **INT**___**MAX)** full motion estimation(slowest) **(768,** **1024]** umh motion estimation **(512,** **768]** hex motion estimation **(256,** **512]** l2s diamond motion estimation **[2,256]** var diamond motion estimation **(-1,** **2)** small diamond motion estimation **-1** funny diamond motion estimation **(INT**___**MIN,** **-1)** sab diamond motion estimation **last**___**pred** _integer_ **(**_encoding,video_**)** Set amount of motion predictors from the previous frame. **preme** _integer_ **(**_encoding,video_**)** Set pre motion estimation. **precmp** _integer_ **(**_encoding,video_**)** Set pre motion estimation compare function. Possible values: **sad** sum of absolute differences, fast (default) **sse** sum of squared errors **satd** sum of absolute Hadamard transformed differences **dct** sum of absolute DCT transformed differences **psnr** sum of squared quantization errors (avoid, low quality) **bit** number of bits needed for the block **rd** rate distortion optimal, slow **zero** 0 **vsad** sum of absolute vertical differences **vsse** sum of squared vertical differences **nsse** noise preserving sum of squared differences **w53** 5/3 wavelet, only used in snow **w97** 9/7 wavelet, only used in snow **dctmax** **chroma** **pre**___**dia**___**size** _integer_ **(**_encoding,video_**)** Set diamond type & size for motion estimation pre-pass. **subq** _integer_ **(**_encoding,video_**)** Set sub pel motion estimation quality. **me**___**range** _integer_ **(**_encoding,video_**)** Set limit motion vectors range (1023 for DivX player). **global**___**quality** _integer_ **(**_encoding,audio,video_**)** **coder** _integer_ **(**_encoding,video_**)** Possible values: **vlc** variable length coder / huffman coder **ac** arithmetic coder **raw** raw (no encoding) **rle** run-length coder **context** _integer_ **(**_encoding,video_**)** Set context model. **slice**___**flags** _integer_ **mbd** _integer_ **(**_encoding,video_**)** Set macroblock decision algorithm (high quality mode). Possible values: **simple** use mbcmp (default) **bits** use fewest bits **rd** use best rate distortion **sc**___**threshold** _integer_ **(**_encoding,video_**)** Set scene change threshold. **nr** _integer_ **(**_encoding,video_**)** Set noise reduction. **rc**___**init**___**occupancy** _integer_ **(**_encoding,video_**)** Set number of bits which should be loaded into the rc buffer before decoding starts. **flags2** _flags_ **(**_decoding/encoding,audio,video,subtitles_**)** Possible values: **fast** Allow non spec compliant speedup tricks. **noout** Skip bitstream encoding. **ignorecrop** Ignore cropping information from sps. **local**___**header** Place global headers at every keyframe instead of in extradata. **chunks** Frame data might be split into multiple chunks. **showall** Show all frames before the first keyframe. **export**___**mvs** Export motion vectors into frame side-data (see "AV_FRAME_DATA_MOTION_VECTORS") for codecs that support it. See also _doc/examples/export_mvs.c_. **skip**___**manual** Do not skip samples and export skip information as frame side data. **ass**___**ro**___**flush**___**noop** Do not reset ASS ReadOrder field on flush. **export**___**side**___**data** _flags_ **(**_decoding/encoding,audio,video,subtitles_**)** Possible values: **mvs** Export motion vectors into frame side-data (see "AV_FRAME_DATA_MOTION_VECTORS") for codecs that support it. See also _doc/examples/export_mvs.c_. **prft** Export encoder Producer Reference Time into packet side-data (see "AV_PKT_DATA_PRFT") for codecs that support it. **venc**___**params** Export video encoding parameters through frame side data (see "AV_FRAME_DATA_VIDEO_ENC_PARAMS") for codecs that support it. At present, those are H.264 and VP9. **film**___**grain** Export film grain parameters through frame side data (see "AV_FRAME_DATA_FILM_GRAIN_PARAMS"). Supported at present by AV1 decoders. **threads** _integer_ **(**_decoding/encoding,video_**)** Set the number of threads to be used, in case the selected codec implementation supports multi-threading. Possible values: **auto,** **0** automatically select the number of threads to set Default value is **auto**. **dc** _integer_ **(**_encoding,video_**)** Set intra_dc_precision. **nssew** _integer_ **(**_encoding,video_**)** Set nsse weight. **skip**___**top** _integer_ **(**_decoding,video_**)** Set number of macroblock rows at the top which are skipped. **skip**___**bottom** _integer_ **(**_decoding,video_**)** Set number of macroblock rows at the bottom which are skipped. **profile** _integer_ **(**_encoding,audio,video_**)** Set encoder codec profile. Default value is **unknown**. Encoder specific profiles are documented in the relevant encoder documentation. **level** _integer_ **(**_encoding,audio,video_**)** Possible values: **unknown** **lowres** _integer_ **(**_decoding,audio,video_**)** Decode at 1= 1/2, 2=1/4, 3=1/8 resolutions. **skip**___**threshold** _integer_ **(**_encoding,video_**)** Set frame skip threshold. **skip**___**factor** _integer_ **(**_encoding,video_**)** Set frame skip factor. **skip**___**exp** _integer_ **(**_encoding,video_**)** Set frame skip exponent. Negative values behave identical to the corresponding positive ones, except that the score is normalized. Positive values exist primarily for compatibility reasons and are not so useful. **skipcmp** _integer_ **(**_encoding,video_**)** Set frame skip compare function. Possible values: **sad** sum of absolute differences, fast (default) **sse** sum of squared errors **satd** sum of absolute Hadamard transformed differences **dct** sum of absolute DCT transformed differences **psnr** sum of squared quantization errors (avoid, low quality) **bit** number of bits needed for the block **rd** rate distortion optimal, slow **zero** 0 **vsad** sum of absolute vertical differences **vsse** sum of squared vertical differences **nsse** noise preserving sum of squared differences **w53** 5/3 wavelet, only used in snow **w97** 9/7 wavelet, only used in snow **dctmax** **chroma** **mblmin** _integer_ **(**_encoding,video_**)** Set min macroblock lagrange factor (VBR). **mblmax** _integer_ **(**_encoding,video_**)** Set max macroblock lagrange factor (VBR). **mepc** _integer_ **(**_encoding,video_**)** Set motion estimation bitrate penalty compensation (1.0 = 256). **skip**___**loop**___**filter** _integer_ **(**_decoding,video_**)** **skip**___**idct** _integer_ **(**_decoding,video_**)** **skip**___**frame** _integer_ **(**_decoding,video_**)** Make decoder discard processing depending on the frame type selected by the option value. **skip**___**loop**___**filter** skips frame loop filtering, **skip**___**idct** skips frame IDCT/dequantization, **skip**___**frame** skips decoding. Possible values: **none** Discard no frame. **default** Discard useless frames like 0-sized frames. **noref** Discard all non-reference frames. **bidir** Discard all bidirectional frames. **nokey** Discard all frames excepts keyframes. **nointra** Discard all frames except I frames. **all** Discard all frames. Default value is **default**. **bidir**___**refine** _integer_ **(**_encoding,video_**)** Refine the two motion vectors used in bidirectional macroblocks. **brd**___**scale** _integer_ **(**_encoding,video_**)** Downscale frames for dynamic B-frame decision. **keyint**___**min** _integer_ **(**_encoding,video_**)** Set minimum interval between IDR-frames. **refs** _integer_ **(**_encoding,video_**)** Set reference frames to consider for motion compensation. **chromaoffset** _integer_ **(**_encoding,video_**)** Set chroma qp offset from luma. **trellis** _integer_ **(**_encoding,audio,video_**)** Set rate-distortion optimal quantization. **mv0**___**threshold** _integer_ **(**_encoding,video_**)** **b**___**sensitivity** _integer_ **(**_encoding,video_**)** Adjust sensitivity of b_frame_strategy 1. **compression**___**level** _integer_ **(**_encoding,audio,video_**)** **min**___**prediction**___**order** _integer_ **(**_encoding,audio_**)** **max**___**prediction**___**order** _integer_ **(**_encoding,audio_**)** **timecode**___**frame**___**start** _integer_ **(**_encoding,video_**)** Set GOP timecode frame start number, in non drop frame format. **bits**___**per**___**raw**___**sample** _integer_ **channel**___**layout** _integer_ **(**_decoding/encoding,audio_**)** Possible values: **request**___**channel**___**layout** _integer_ **(**_decoding,audio_**)** Possible values: **rc**___**max**___**vbv**___**use** _float_ **(**_encoding,video_**)** **rc**___**min**___**vbv**___**use** _float_ **(**_encoding,video_**)** **ticks**___**per**___**frame** _integer_ **(**_decoding/encoding,audio,video_**)** **color**___**primaries** _integer_ **(**_decoding/encoding,video_**)** Possible values: **bt709** BT.709 **bt470m** BT.470 M **bt470bg** BT.470 BG **smpte170m** SMPTE 170 M **smpte240m** SMPTE 240 M **film** Film **bt2020** BT.2020 **smpte428** **smpte428**___**1** SMPTE ST 428-1 **smpte431** SMPTE 431-2 **smpte432** SMPTE 432-1 **jedec-p22** JEDEC P22 **color**___**trc** _integer_ **(**_decoding/encoding,video_**)** Possible values: **bt709** BT.709 **gamma22** BT.470 M **gamma28** BT.470 BG **smpte170m** SMPTE 170 M **smpte240m** SMPTE 240 M **linear** Linear **log** **log100** Log **log**___**sqrt** **log316** Log square root **iec61966**___**2**___**4** **iec61966-2-4** IEC 61966-2-4 **bt1361** **bt1361e** BT.1361 **iec61966**___**2**___**1** **iec61966-2-1** IEC 61966-2-1 **bt2020**___**10** **bt2020**___**10bit** BT.2020 - 10 bit **bt2020**___**12** **bt2020**___**12bit** BT.2020 - 12 bit **smpte2084** SMPTE ST 2084 **smpte428** **smpte428**___**1** SMPTE ST 428-1 **arib-std-b67** ARIB STD-B67 **colorspace** _integer_ **(**_decoding/encoding,video_**)** Possible values: **rgb** RGB **bt709** BT.709 **fcc** FCC **bt470bg** BT.470 BG **smpte170m** SMPTE 170 M **smpte240m** SMPTE 240 M **ycocg** YCOCG **bt2020nc** **bt2020**___**ncl** BT.2020 NCL **bt2020c** **bt2020**___**cl** BT.2020 CL **smpte2085** SMPTE 2085 **chroma-derived-nc** Chroma-derived NCL **chroma-derived-c** Chroma-derived CL **ictcp** ICtCp **color**___**range** _integer_ **(**_decoding/encoding,video_**)** If used as input parameter, it serves as a hint to the decoder, which color_range the input has. Possible values: **tv** **mpeg** MPEG (219*2^(n-8)) **pc** **jpeg** JPEG (2^n-1) **chroma**___**sample**___**location** _integer_ **(**_decoding/encoding,video_**)** Possible values: **left** **center** **topleft** **top** **bottomleft** **bottom** **log**___**level**___**offset** _integer_ Set the log level offset. **slices** _integer_ **(**_encoding,video_**)** Number of slices, used in parallelized encoding. **thread**___**type** _flags_ **(**_decoding/encoding,video_**)** Select which multithreading methods to use. Use of **frame** will increase decoding delay by one frame per thread, so clients which cannot provide future frames should not use it. Possible values: **slice** Decode more than one part of a single frame at once. Multithreading using slices works only when the video was encoded with slices. **frame** Decode more than one frame at once. Default value is **slice+frame**. **audio**___**service**___**type** _integer_ **(**_encoding,audio_**)** Set audio service type. Possible values: **ma** Main Audio Service **ef** Effects **vi** Visually Impaired **hi** Hearing Impaired **di** Dialogue **co** Commentary **em** Emergency **vo** Voice Over **ka** Karaoke **request**___**sample**___**fmt** _sample_fmt_ **(**_decoding,audio_**)** Set sample format audio decoders should prefer. Default value is "none". **pkt**___**timebase** _rational_ _number_ **sub**___**charenc** _encoding_ **(**_decoding,subtitles_**)** Set the input subtitles character encoding. **field**___**order** _field_order_ **(**_video_**)** Set/override the field order of the video. Possible values: **progressive** Progressive video **tt** Interlaced video, top field coded and displayed first **bb** Interlaced video, bottom field coded and displayed first **tb** Interlaced video, top coded first, bottom displayed first **bt** Interlaced video, bottom coded first, top displayed first **skip**___**alpha** _bool_ **(**_decoding,video_**)** Set to 1 to disable processing alpha (transparency). This works like the **gray** flag in the **flags** option which skips chroma information instead of alpha. Default is 0. **codec**___**whitelist** _list_ **(**_input_**)** "," separated list of allowed decoders. By default all are allowed. **dump**___**separator** _string_ **(**_input_**)** Separator used to separate the fields printed on the command line about the Stream parameters. For example, to separate the fields with newlines and indentation: ffprobe -dump_separator " " -i ~/videos/matrixbench_mpeg2.mpg **max**___**pixels** _integer_ **(**_decoding/encoding,video_**)** Maximum number of pixels per image. This value can be used to avoid out of memory failures due to large images. **apply**___**cropping** _bool_ **(**_decoding,video_**)** Enable cropping if cropping parameters are multiples of the required alignment for the left and top parameters. If the alignment is not met the cropping will be partially applied to maintain alignment. Default is 1 (enabled). Note: The required alignment depends on if "AV_CODEC_FLAG_UNALIGNED" is set and the CPU. "AV_CODEC_FLAG_UNALIGNED" cannot be changed from the command line. Also hardware decoders will not apply left/top Cropping. ## DECODERS Decoders are configured elements in FFmpeg which allow the decoding of multimedia streams. When you configure your FFmpeg build, all the supported native decoders are enabled by default. Decoders requiring an external library must be enabled manually via the corresponding "--enable-lib" option. You can list all available decoders using the configure option "--list-decoders". You can disable all the decoders with the configure option "--disable-decoders" and selectively enable / disable single decoders with the options "--enable-decoder=_DECODER"_ / "--disable-decoder=_DECODER"_. The option "-decoders" of the ff* tools will display the list of enabled decoders. ## VIDEO DECODERS A description of some of the currently available video decoders follows. ### av1 AOMedia Video 1 (AV1) decoder. _Options_ **operating**___**point** Select an operating point of a scalable AV1 bitstream (0 - 31). Default is 0. ### rawvideo Raw video decoder. This decoder decodes rawvideo streams. _Options_ **top** _top_field_first_ Specify the assumed field type of the input video. **-1** the video is assumed to be progressive (default) **0** bottom-field-first is assumed **1** top-field-first is assumed ### libdav1d dav1d AV1 decoder. libdav1d allows libavcodec to decode the AOMedia Video 1 (AV1) codec. Requires the presence of the libdav1d headers and library during configuration. You need to explicitly configure the build with "--enable-libdav1d". _Options_ The following options are supported by the libdav1d wrapper. ### framethreads Set amount of frame threads to use during decoding. The default value is 0 (autodetect). ### tilethreads Set amount of tile threads to use during decoding. The default value is 0 (autodetect). ### filmgrain Apply film grain to the decoded video if present in the bitstream. Defaults to the internal default of the library. ### oppoint Select an operating point of a scalable AV1 bitstream (0 - 31). Defaults to the internal default of the library. ### alllayers Output all spatial layers of a scalable AV1 bitstream. The default value is false. ### libdavs2 AVS2-P2/IEEE1857.4 video decoder wrapper. This decoder allows libavcodec to decode AVS2 streams with davs2 library. ### libuavs3d AVS3-P2/IEEE1857.10 video decoder. libuavs3d allows libavcodec to decode AVS3 streams. Requires the presence of the libuavs3d headers and library during configuration. You need to explicitly configure the build with "--enable-libuavs3d". _Options_ The following option is supported by the libuavs3d wrapper. **frame**___**threads** Set amount of frame threads to use during decoding. The default value is 0 (autodetect). ## AUDIO DECODERS A description of some of the currently available audio decoders follows. ### ac3 AC-3 audio decoder. This decoder implements part of ATSC A/52:2010 and ETSI TS 102 366, as well as the undocumented RealAudio 3 (a.k.a. dnet). _AC-3_ _Decoder_ _Options_ ### -drc Dynamic Range Scale Factor. The factor to apply to dynamic range values from the AC-3 stream. This factor is applied exponentially. The default value is 1. There are 3 notable scale factor ranges: **drc**___**scale** **==** **0** DRC disabled. Produces full range audio. **0** **<** **drc**___**scale** **<=** **1** DRC enabled. Applies a fraction of the stream DRC value. Audio reproduction is between full range and full compression. **drc**___**scale** **>** **1** DRC enabled. Applies drc_scale asymmetrically. Loud sounds are fully compressed. Soft sounds are enhanced. ### flac FLAC audio decoder. This decoder aims to implement the complete FLAC specification from Xiph. _FLAC_ _Decoder_ _options_ ### -use The lavc FLAC encoder used to produce buggy streams with high lpc values (like the default value). This option makes it possible to decode such streams correctly by using lavc's old buggy lpc logic for decoding. ### ffwavesynth Internal wave synthesizer. This decoder generates wave patterns according to predefined sequences. Its use is purely internal and the format of the data it accepts is not publicly documented. ### libcelt libcelt decoder wrapper. libcelt allows libavcodec to decode the Xiph CELT ultra-low delay audio codec. Requires the presence of the libcelt headers and library during configuration. You need to explicitly configure the build with "--enable-libcelt". ### libgsm libgsm decoder wrapper. libgsm allows libavcodec to decode the GSM full rate audio codec. Requires the presence of the libgsm headers and library during configuration. You need to explicitly configure the build with "--enable-libgsm". This decoder supports both the ordinary GSM and the Microsoft variant. ### libilbc libilbc decoder wrapper. libilbc allows libavcodec to decode the Internet Low Bitrate Codec (iLBC) audio codec. Requires the presence of the libilbc headers and library during configuration. You need to explicitly configure the build with "--enable-libilbc". _Options_ The following option is supported by the libilbc wrapper. ### enhance Enable the enhancement of the decoded audio when set to 1. The default value is 0 (disabled). ### libopencore-amrnb libopencore-amrnb decoder wrapper. libopencore-amrnb allows libavcodec to decode the Adaptive Multi-Rate Narrowband audio codec. Using it requires the presence of the libopencore-amrnb headers and library during configuration. You need to explicitly configure the build with "--enable-libopencore-amrnb". An FFmpeg native decoder for AMR-NB exists, so users can decode AMR-NB without this library. ### libopencore-amrwb libopencore-amrwb decoder wrapper. libopencore-amrwb allows libavcodec to decode the Adaptive Multi-Rate Wideband audio codec. Using it requires the presence of the libopencore-amrwb headers and library during configuration. You need to explicitly configure the build with "--enable-libopencore-amrwb". An FFmpeg native decoder for AMR-WB exists, so users can decode AMR-WB without this library. ### libopus libopus decoder wrapper. libopus allows libavcodec to decode the Opus Interactive Audio Codec. Requires the presence of the libopus headers and library during configuration. You need to explicitly configure the build with "--enable-libopus". An FFmpeg native decoder for Opus exists, so users can decode Opus without this library. ## SUBTITLES DECODERS ### libaribb24 ARIB STD-B24 caption decoder. Implements profiles A and C of the ARIB STD-B24 standard. _libaribb24_ _Decoder_ _Options_ ### -aribb24-base-path Sets the base path for the libaribb24 library. This is utilized for reading of configuration files (for custom unicode conversions), and for dumping of non-text symbols as images under that location. Unset by default. ### -aribb24-skip-ruby-text Tells the decoder wrapper to skip text blocks that contain half-height ruby text. Enabled by default. ### dvbsub _Options_ **compute**___**clut** **-1** Compute clut if no matching CLUT is in the stream. **0** Never compute CLUT **1** Always compute CLUT and override the one provided in the stream. **dvb**___**substream** Selects the dvb substream, or all substreams if -1 which is default. ### dvdsub This codec decodes the bitmap subtitles used in DVDs; the same subtitles can also be found in VobSub file pairs and in some Matroska files. _Options_ ### palette Specify the global palette used by the bitmaps. When stored in VobSub, the palette is normally specified in the index file; in Matroska, the palette is stored in the codec extra-data in the same format as in VobSub. In DVDs, the palette is stored in the IFO file, and therefore not available when reading from dumped VOB files. The format for this option is a string containing 16 24-bits hexadecimal numbers (without 0x prefix) separated by commas, for example "0d00ee, ee450d, 101010, eaeaea, 0ce60b, ec14ed, ebff0b, 0d617a, 7b7b7b, d1d1d1, 7b2a0e, 0d950c, 0f007b, cf0dec, cfa80c, 7c127b". **ifo**___**palette** Specify the IFO file from which the global palette is obtained. (experimental) **forced**___**subs**___**only** Only decode subtitle entries marked as forced. Some titles have forced and non-forced subtitles in the same track. Setting this flag to 1 will only keep the forced subtitles. Default value is 0. ### libzvbi-teletext Libzvbi allows libavcodec to decode DVB teletext pages and DVB teletext subtitles. Requires the presence of the libzvbi headers and library during configuration. You need to explicitly configure the build with "--enable-libzvbi". _Options_ **txt**___**page** List of teletext page numbers to decode. Pages that do not match the specified list are dropped. You may use the special "*" string to match all pages, or "subtitle" to match all subtitle pages. Default value is *. **txt**___**default**___**region** Set default character set used for decoding, a value between 0 and 87 (see ETS 300 706, Section 15, Table 32). Default value is -1, which does not override the libzvbi default. This option is needed for some legacy level 1.0 transmissions which cannot signal the proper charset. **txt**___**chop**___**top** Discards the top teletext line. Default value is 1. **txt**___**format** Specifies the format of the decoded subtitles. **bitmap** The default format, you should use this for teletext pages, because certain graphics and colors cannot be expressed in simple text or even ASS. **text** Simple text based output without formatting. **ass** Formatted ASS output, subtitle pages and teletext pages are returned in different styles, subtitle pages are stripped down to text, but an effort is made to keep the text alignment and the formatting. **txt**___**left** X offset of generated bitmaps, default is 0. **txt**___**top** Y offset of generated bitmaps, default is 0. **txt**___**chop**___**spaces** Chops leading and trailing spaces and removes empty lines from the generated text. This option is useful for teletext based subtitles where empty spaces may be present at the start or at the end of the lines or empty lines may be present between the subtitle lines because of double-sized teletext characters. Default value is 1. **txt**___**duration** Sets the display duration of the decoded teletext pages or subtitles in milliseconds. Default value is -1 which means infinity or until the next subtitle event comes. **txt**___**transparent** Force transparent background of the generated teletext bitmaps. Default value is 0 which means an opaque background. **txt**___**opacity** Sets the opacity (0-255) of the teletext background. If **txt**___**transparent** is not set, it only affects characters between a start box and an end box, typically subtitles. Default value is 0 if **txt**___**transparent** is set, 255 otherwise. ## BITSTREAM FILTERS When you configure your FFmpeg build, all the supported bitstream filters are enabled by default. You can list all available ones using the configure option "--list-bsfs". You can disable all the bitstream filters using the configure option "--disable-bsfs", and selectively enable any bitstream filter using the option "--enable-bsf=BSF", or you can disable a particular bitstream filter using the option "--disable-bsf=BSF". The option "-bsfs" of the ff* tools will display the list of all the supported bitstream filters included in your build. The ff* tools have a -bsf option applied per stream, taking a comma-separated list of filters, whose parameters follow the filter name after a '='. ffmpeg -i INPUT -c:v copy -bsf:v filter1[=opt1=str1:opt2=str2][,filter2] OUTPUT Below is a description of the currently available bitstream filters, with their parameters, if any. **aac**___**adtstoasc** Convert MPEG-2/4 AAC ADTS to an MPEG-4 Audio Specific Configuration bitstream. This filter creates an MPEG-4 AudioSpecificConfig from an MPEG-2/4 ADTS header and removes the ADTS header. This filter is required for example when copying an AAC stream from a raw ADTS AAC or an MPEG-TS container to MP4A-LATM, to an FLV file, or to MOV/MP4 files and related formats such as 3GP or M4A. Please note that it is auto-inserted for MP4A-LATM and MOV/MP4 and related formats. **av1**___**metadata** Modify metadata embedded in an AV1 stream. **td** Insert or remove temporal delimiter OBUs in all temporal units of the stream. **insert** Insert a TD at the beginning of every TU which does not already have one. **remove** Remove the TD from the beginning of every TU which has one. **color**___**primaries** **transfer**___**characteristics** **matrix**___**coefficients** Set the color description fields in the stream (see AV1 section 6.4.2). **color**___**range** Set the color range in the stream (see AV1 section 6.4.2; note that this cannot be set for streams using BT.709 primaries, sRGB transfer characteristic and identity (RGB) matrix coefficients). **tv** Limited range. **pc** Full range. **chroma**___**sample**___**position** Set the chroma sample location in the stream (see AV1 section 6.4.2). This can only be set for 4:2:0 streams. **vertical** Left position (matching the default in MPEG-2 and H.264). **colocated** Top-left position. **tick**___**rate** Set the tick rate (_num_units_in_display_tick_ _/_ _time_scale_) in the timing info in the sequence header. **num**___**ticks**___**per**___**picture** Set the number of ticks in each picture, to indicate that the stream has a fixed framerate. Ignored if **tick**___**rate** is not also set. **delete**___**padding** Deletes Padding OBUs. ### chomp Remove zero padding at the end of a packet. **dca**___**core** Extract the core from a DCA/DTS stream, dropping extensions such as DTS-HD. **dump**___**extra** Add extradata to the beginning of the filtered packets except when said packets already exactly begin with the extradata that is intended to be added. ### freq The additional argument specifies which packets should be filtered. It accepts the values: **k** **keyframe** add extradata to all key packets **e** **all** add extradata to all packets If not specified it is assumed **k**. For example the following **ffmpeg** command forces a global header (thus disabling individual packet headers) in the H.264 packets generated by the "libx264" encoder, but corrects them by adding the header stored in extradata to the key packets: ffmpeg -i INPUT -map 0 -flags:v +global_header -c:v libx264 -bsf:v dump_extra out.ts **eac3**___**core** Extract the core from a E-AC-3 stream, dropping extra channels. **extract**___**extradata** Extract the in-band extradata. Certain codecs allow the long-term headers (e.g. MPEG-2 sequence headers, or H.264/HEVC (VPS/)SPS/PPS) to be transmitted either "in-band" (i.e. as a part of the bitstream containing the coded frames) or "out of band" (e.g. on the container level). This latter form is called "extradata" in FFmpeg terminology. This bitstream filter detects the in-band headers and makes them available as extradata. ### remove When this option is enabled, the long-term headers are removed from the bitstream after extraction. **filter**___**units** Remove units with types in or not in a given set from the stream. **pass**___**types** List of unit types or ranges of unit types to pass through while removing all others. This is specified as a '|'-separated list of unit type values or ranges of values with '-'. **remove**___**types** Identical to **pass**___**types**, except the units in the given set removed and all others passed through. Extradata is unchanged by this transformation, but note that if the stream contains inline parameter sets then the output may be unusable if they are removed. For example, to remove all non-VCL NAL units from an H.264 stream: ffmpeg -i INPUT -c:v copy -bsf:v 'filter_units=pass_types=1-5' OUTPUT To remove all AUDs, SEI and filler from an H.265 stream: ffmpeg -i INPUT -c:v copy -bsf:v 'filter_units=remove_types=35|38-40' OUTPUT **hapqa**___**extract** Extract Rgb or Alpha part of an HAPQA file, without recompression, in order to create an HAPQ or an HAPAlphaOnly file. ### texture Specifies the texture to keep. **color** **alpha** Convert HAPQA to HAPQ ffmpeg -i hapqa_inputfile.mov -c copy -bsf:v hapqa_extract=texture=color -tag:v HapY -metadata:s:v:0 encoder="HAPQ" hapq_file.mov Convert HAPQA to HAPAlphaOnly ffmpeg -i hapqa_inputfile.mov -c copy -bsf:v hapqa_extract=texture=alpha -tag:v HapA -metadata:s:v:0 encoder="HAPAlpha Only" hapalphaonly_file.mov **h264**___**metadata** Modify metadata embedded in an H.264 stream. **aud** Insert or remove AUD NAL units in all access units of the stream. **insert** **remove** **sample**___**aspect**___**ratio** Set the sample aspect ratio of the stream in the VUI parameters. **overscan**___**appropriate**___**flag** Set whether the stream is suitable for display using overscan or not (see H.264 section E.2.1). **video**___**format** **video**___**full**___**range**___**flag** Set the video format in the stream (see H.264 section E.2.1 and table E-2). **colour**___**primaries** **transfer**___**characteristics** **matrix**___**coefficients** Set the colour description in the stream (see H.264 section E.2.1 and tables E-3, E-4 and E-5). **chroma**___**sample**___**loc**___**type** Set the chroma sample location in the stream (see H.264 section E.2.1 and figure E-1). **tick**___**rate** Set the tick rate (num_units_in_tick / time_scale) in the VUI parameters. This is the smallest time unit representable in the stream, and in many cases represents the field rate of the stream (double the frame rate). **fixed**___**frame**___**rate**___**flag** Set whether the stream has fixed framerate - typically this indicates that the framerate is exactly half the tick rate, but the exact meaning is dependent on interlacing and the picture structure (see H.264 section E.2.1 and table E-6). **crop**___**left** **crop**___**right** **crop**___**top** **crop**___**bottom** Set the frame cropping offsets in the SPS. These values will replace the current ones if the stream is already cropped. These fields are set in pixels. Note that some sizes may not be representable if the chroma is subsampled or the stream is interlaced (see H.264 section 7.4.2.1.1). **sei**___**user**___**data** Insert a string as SEI unregistered user data. The argument must be of the form _UUID+string_, where the UUID is as hex digits possibly separated by hyphens, and the string can be anything. For example, **086f3693-b7b3-4f2c-9653-21492feee5b8+hello** will insert the string ``hello'' associated with the given UUID. **delete**___**filler** Deletes both filler NAL units and filler SEI messages. ### level Set the level in the SPS. Refer to H.264 section A.3 and tables A-1 to A-5. The argument must be the name of a level (for example, **4.2**), a level_idc value (for example, **42**), or the special name **auto** indicating that the filter should attempt to guess the level from the input stream properties. **h264**___**mp4toannexb** Convert an H.264 bitstream from length prefixed mode to start code prefixed mode (as defined in the Annex B of the ITU-T H.264 specification). This is required by some streaming formats, typically the MPEG-2 transport stream format (muxer "mpegts"). For example to remux an MP4 file containing an H.264 stream to mpegts format with **ffmpeg**, you can use the command: ffmpeg -i INPUT.mp4 -codec copy -bsf:v h264_mp4toannexb OUTPUT.ts Please note that this filter is auto-inserted for MPEG-TS (muxer "mpegts") and raw H.264 (muxer "h264") output formats. **h264**___**redundant**___**pps** This applies a specific fixup to some Blu-ray streams which contain redundant PPSs modifying irrelevant parameters of the stream which confuse other transformations which require correct extradata. A new single global PPS is created, and all of the redundant PPSs within the stream are removed. **hevc**___**metadata** Modify metadata embedded in an HEVC stream. **aud** Insert or remove AUD NAL units in all access units of the stream. **insert** **remove** **sample**___**aspect**___**ratio** Set the sample aspect ratio in the stream in the VUI parameters. **video**___**format** **video**___**full**___**range**___**flag** Set the video format in the stream (see H.265 section E.3.1 and table E.2). **colour**___**primaries** **transfer**___**characteristics** **matrix**___**coefficients** Set the colour description in the stream (see H.265 section E.3.1 and tables E.3, E.4 and E.5). **chroma**___**sample**___**loc**___**type** Set the chroma sample location in the stream (see H.265 section E.3.1 and figure E.1). **tick**___**rate** Set the tick rate in the VPS and VUI parameters (num_units_in_tick / time_scale). Combined with **num**___**ticks**___**poc**___**diff**___**one**, this can set a constant framerate in the stream. Note that it is likely to be overridden by container parameters when the stream is in a container. **num**___**ticks**___**poc**___**diff**___**one** Set poc_proportional_to_timing_flag in VPS and VUI and use this value to set num_ticks_poc_diff_one_minus1 (see H.265 sections 7.4.3.1 and E.3.1). Ignored if **tick**___**rate** is not also set. **crop**___**left** **crop**___**right** **crop**___**top** **crop**___**bottom** Set the conformance window cropping offsets in the SPS. These values will replace the current ones if the stream is already cropped. These fields are set in pixels. Note that some sizes may not be representable if the chroma is subsampled (H.265 section 7.4.3.2.1). ### level Set the level in the VPS and SPS. See H.265 section A.4 and tables A.6 and A.7. The argument must be the name of a level (for example, **5.1**), a _general_level_idc_ value (for example, **153** for level 5.1), or the special name **auto** indicating that the filter should attempt to guess the level from the input stream properties. **hevc**___**mp4toannexb** Convert an HEVC/H.265 bitstream from length prefixed mode to start code prefixed mode (as defined in the Annex B of the ITU-T H.265 specification). This is required by some streaming formats, typically the MPEG-2 transport stream format (muxer "mpegts"). For example to remux an MP4 file containing an HEVC stream to mpegts format with **ffmpeg**, you can use the command: ffmpeg -i INPUT.mp4 -codec copy -bsf:v hevc_mp4toannexb OUTPUT.ts Please note that this filter is auto-inserted for MPEG-TS (muxer "mpegts") and raw HEVC/H.265 (muxer "h265" or "hevc") output formats. ### imxdump Modifies the bitstream to fit in MOV and to be usable by the Final Cut Pro decoder. This filter only applies to the mpeg2video codec, and is likely not needed for Final Cut Pro 7 and newer with the appropriate **-tag:v**. For example, to remux 30 MB/sec NTSC IMX to MOV: ffmpeg -i input.mxf -c copy -bsf:v imxdump -tag:v mx3n output.mov ### mjpeg2jpeg Convert MJPEG/AVI1 packets to full JPEG/JFIF packets. MJPEG is a video codec wherein each video frame is essentially a JPEG image. The individual frames can be extracted without loss, e.g. by ffmpeg -i ../some_mjpeg.avi -c:v copy frames_%d.jpg Unfortunately, these chunks are incomplete JPEG images, because they lack the DHT segment required for decoding. Quoting from <****>: Avery Lee, writing in the rec.video.desktop newsgroup in 2001, commented that "MJPEG, or at least the MJPEG in AVIs having the MJPG fourcc, is restricted JPEG with a fixed -- and *omitted* -- Huffman table. The JPEG must be YCbCr colorspace, it must be 4:2:2, and it must use basic Huffman encoding, not arithmetic or progressive. . . . You can indeed extract the MJPEG frames and decode them with a regular JPEG decoder, but you have to prepend the DHT segment to them, or else the decoder won't have any idea how to decompress the data. The exact table necessary is given in the OpenDML spec." This bitstream filter patches the header of frames extracted from an MJPEG stream (carrying the AVI1 header ID and lacking a DHT segment) to produce fully qualified JPEG images. ffmpeg -i mjpeg-movie.avi -c:v copy -bsf:v mjpeg2jpeg frame_%d.jpg exiftran -i -9 frame*.jpg ffmpeg -i frame_%d.jpg -c:v copy rotated.avi ### mjpegadump Add an MJPEG A header to the bitstream, to enable decoding by Quicktime. ### mov2textsub Extract a representable text file from MOV subtitles, stripping the metadata header from each subtitle packet. See also the **text2movsub** filter. ### mp3decomp Decompress non-standard compressed MP3 audio headers. **mpeg2**___**metadata** Modify metadata embedded in an MPEG-2 stream. **display**___**aspect**___**ratio** Set the display aspect ratio in the stream. The following fixed values are supported: **4/3** **16/9** **221/100** Any other value will result in square pixels being signalled instead (see H.262 section 6.3.3 and table 6-3). **frame**___**rate** Set the frame rate in the stream. This is constructed from a table of known values combined with a small multiplier and divisor - if the supplied value is not exactly representable, the nearest representable value will be used instead (see H.262 section 6.3.3 and table 6-4). **video**___**format** Set the video format in the stream (see H.262 section 6.3.6 and table 6-6). **colour**___**primaries** **transfer**___**characteristics** **matrix**___**coefficients** Set the colour description in the stream (see H.262 section 6.3.6 and tables 6-7, 6-8 and 6-9). **mpeg4**___**unpack**___**bframes** Unpack DivX-style packed B-frames. DivX-style packed B-frames are not valid MPEG-4 and were only a workaround for the broken Video for Windows subsystem. They use more space, can cause minor AV sync issues, require more CPU power to decode (unless the player has some decoded picture queue to compensate the 2,0,2,0 frame per packet style) and cause trouble if copied into a standard container like mp4 or mpeg-ps/ts, because MPEG-4 decoders may not be able to decode them, since they are not valid MPEG-4. For example to fix an AVI file containing an MPEG-4 stream with DivX-style packed B-frames using **ffmpeg**, you can use the command: ffmpeg -i INPUT.avi -codec copy -bsf:v mpeg4_unpack_bframes OUTPUT.avi ### noise Damages the contents of packets or simply drops them without damaging the container. Can be used for fuzzing or testing error resilience/concealment. Parameters: ### amount A numeral string, whose value is related to how often output bytes will be modified. Therefore, values below or equal to 0 are forbidden, and the lower the more frequent bytes will be modified, with 1 meaning every byte is modified. ### dropamount A numeral string, whose value is related to how often packets will be dropped. Therefore, values below or equal to 0 are forbidden, and the lower the more frequent packets will be dropped, with 1 meaning every packet is dropped. The following example applies the modification to every byte but does not drop any packets. ffmpeg -i INPUT -c copy -bsf noise[=1] output.mkv ### null This bitstream filter passes the packets through unchanged. **pcm**___**rechunk** Repacketize PCM audio to a fixed number of samples per packet or a fixed packet rate per second. This is similar to the **asetnsamples** **audio** **filter** but works on audio packets instead of audio frames. **nb**___**out**___**samples,** **n** Set the number of samples per each output audio packet. The number is intended as the number of samples _per_ _each_ _channel_. Default value is 1024. ### pad, p If set to 1, the filter will pad the last audio packet with silence, so that it will contain the same number of samples (or roughly the same number of samples, see **frame**___**rate**) as the previous ones. Default value is 1. **frame**___**rate,** **r** This option makes the filter output a fixed number of packets per second instead of a fixed number of samples per packet. If the audio sample rate is not divisible by the frame rate then the number of samples will not be constant but will vary slightly so that each packet will start as close to the frame boundary as possible. Using this option has precedence over **nb**___**out**___**samples**. You can generate the well known 1602-1601-1602-1601-1602 pattern of 48kHz audio for NTSC frame rate using the **frame**___**rate** option. ffmpeg -f lavfi -i sine=r=48000:d=1 -c pcm_s16le -bsf pcm_rechunk=r=30000/1001 -f framecrc - **prores**___**metadata** Modify color property metadata embedded in prores stream. **color**___**primaries** Set the color primaries. Available values are: **auto** Keep the same color primaries property (default). **unknown** **bt709** **bt470bg** BT601 625 **smpte170m** BT601 525 **bt2020** **smpte431** DCI P3 **smpte432** P3 D65 **transfer**___**characteristics** Set the color transfer. Available values are: **auto** Keep the same transfer characteristics property (default). **unknown** **bt709** BT 601, BT 709, BT 2020 **smpte2084** SMPTE ST 2084 **arib-std-b67** ARIB STD-B67 **matrix**___**coefficients** Set the matrix coefficient. Available values are: **auto** Keep the same colorspace property (default). **unknown** **bt709** **smpte170m** BT 601 **bt2020nc** Set Rec709 colorspace for each frame of the file ffmpeg -i INPUT -c copy -bsf:v prores_metadata=color_primaries=bt709:color_trc=bt709:colorspace=bt709 output.mov Set Hybrid Log-Gamma parameters for each frame of the file ffmpeg -i INPUT -c copy -bsf:v prores_metadata=color_primaries=bt2020:color_trc=arib-std-b67:colorspace=bt2020nc output.mov **remove**___**extra** Remove extradata from packets. It accepts the following parameter: ### freq Set which frame types to remove extradata from. **k** Remove extradata from non-keyframes only. **keyframe** Remove extradata from keyframes only. **e,** **all** Remove extradata from all frames. ### setts Set PTS and DTS in packets. It accepts the following parameters: **ts** ### pts **dts** Set expressions for PTS, DTS or both. The expressions are evaluated through the eval API and can contain the following constants: **N** The count of the input packet. Starting from 0. **TS** The demux timestamp in input in case of "ts" or "dts" option or presentation timestamp in case of "pts" option. **POS** The original position in the file of the packet, or undefined if undefined for the current packet **DTS** The demux timestamp in input. **PTS** The presentation timestamp in input. **STARTDTS** The DTS of the first packet. **STARTPTS** The PTS of the first packet. **PREV**___**INDTS** The previous input DTS. **PREV**___**INPTS** The previous input PTS. **PREV**___**OUTDTS** The previous output DTS. **PREV**___**OUTPTS** The previous output PTS. **TB** The timebase of stream packet belongs. **SR** The sample rate of stream packet belongs. ### text2movsub Convert text subtitles to MOV subtitles (as used by the "mov_text" codec) with metadata headers. See also the **mov2textsub** filter. **trace**___**headers** Log trace output containing all syntax elements in the coded stream headers (everything above the level of individual coded blocks). This can be useful for debugging low-level stream issues. Supports AV1, H.264, H.265, (M)JPEG, MPEG-2 and VP9, but depending on the build only a subset of these may be available. **truehd**___**core** Extract the core from a TrueHD stream, dropping ATMOS data. **vp9**___**metadata** Modify metadata embedded in a VP9 stream. **color**___**space** Set the color space value in the frame header. Note that any frame set to RGB will be implicitly set to PC range and that RGB is incompatible with profiles 0 and 2. **unknown** **bt601** **bt709** **smpte170** **smpte240** **bt2020** **rgb** **color**___**range** Set the color range value in the frame header. Note that any value imposed by the color space will take precedence over this value. **tv** **pc** **vp9**___**superframe** Merge VP9 invisible (alt-ref) frames back into VP9 superframes. This fixes merging of split/segmented VP9 streams where the alt-ref frame was split from its visible counterpart. **vp9**___**superframe**___**split** Split VP9 superframes into single frames. **vp9**___**raw**___**reorder** Given a VP9 stream with correct timestamps but possibly out of order, insert additional show- existing-frame packets to correct the ordering. ## FORMAT OPTIONS The libavformat library provides some generic global options, which can be set on all the muxers and demuxers. In addition each muxer or demuxer may support so-called private options, which are specific for that component. Options may be set by specifying -_option_ _value_ in the FFmpeg tools, or by setting the value explicitly in the "AVFormatContext" options or using the _libavutil/opt.h_ API for programmatic use. The list of supported options follows: **avioflags** _flags_ **(**_input/output_**)** Possible values: **direct** Reduce buffering. **probesize** _integer_ **(**_input_**)** Set probing size in bytes, i.e. the size of the data to analyze to get stream information. A higher value will enable detecting more information in case it is dispersed into the stream, but will increase latency. Must be an integer not lesser than 32. It is 5000000 by default. **max**___**probe**___**packets** _integer_ **(**_input_**)** Set the maximum number of buffered packets when probing a codec. Default is 2500 packets. **packetsize** _integer_ **(**_output_**)** Set packet size. **fflags** _flags_ Set format flags. Some are implemented for a limited number of formats. Possible values for input files: **discardcorrupt** Discard corrupted packets. **fastseek** Enable fast, but inaccurate seeks for some formats. **genpts** Generate missing PTS if DTS is present. **igndts** Ignore DTS if PTS is set. Inert when nofillin is set. **ignidx** Ignore index. **keepside** **(**_deprecated_**,**_inert_**)** **nobuffer** Reduce the latency introduced by buffering during initial input streams analysis. **nofillin** Do not fill in missing values in packet fields that can be exactly calculated. **noparse** Disable AVParsers, this needs "+nofillin" too. **sortdts** Try to interleave output packets by DTS. At present, available only for AVIs with an index. Possible values for output files: **autobsf** Automatically apply bitstream filters as required by the output format. Enabled by default. **bitexact** Only write platform-, build- and time-independent data. This ensures that file and data checksums are reproducible and match between platforms. Its primary use is for regression testing. **flush**___**packets** Write out packets immediately. **latm** **(**_deprecated_**,**_inert_**)** **shortest** Stop muxing at the end of the shortest stream. It may be needed to increase max_interleave_delta to avoid flushing the longer streams before EOF. **seek2any** _integer_ **(**_input_**)** Allow seeking to non-keyframes on demuxer level when supported if set to 1. Default is 0. **analyzeduration** _integer_ **(**_input_**)** Specify how many microseconds are analyzed to probe the input. A higher value will enable detecting more accurate information, but will increase latency. It defaults to 5,000,000 microseconds = 5 seconds. **cryptokey** _hexadecimal_ _string_ **(**_input_**)** Set decryption key. **indexmem** _integer_ **(**_input_**)** Set max memory used for timestamp index (per stream). **rtbufsize** _integer_ **(**_input_**)** Set max memory used for buffering real-time frames. **fdebug** _flags_ **(**_input/output_**)** Print specific debug info. Possible values: **ts** **max**___**delay** _integer_ **(**_input/output_**)** Set maximum muxing or demuxing delay in microseconds. **fpsprobesize** _integer_ **(**_input_**)** Set number of frames used to probe fps. **audio**___**preload** _integer_ **(**_output_**)** Set microseconds by which audio packets should be interleaved earlier. **chunk**___**duration** _integer_ **(**_output_**)** Set microseconds for each chunk. **chunk**___**size** _integer_ **(**_output_**)** Set size in bytes for each chunk. **err**___**detect,** **f**___**err**___**detect** _flags_ **(**_input_**)** Set error detection flags. "f_err_detect" is deprecated and should be used only via the **ffmpeg** tool. Possible values: **crccheck** Verify embedded CRCs. **bitstream** Detect bitstream specification deviations. **buffer** Detect improper bitstream length. **explode** Abort decoding on minor error detection. **careful** Consider things that violate the spec and have not been seen in the wild as errors. **compliant** Consider all spec non compliancies as errors. **aggressive** Consider things that a sane encoder should not do as an error. **max**___**interleave**___**delta** _integer_ **(**_output_**)** Set maximum buffering duration for interleaving. The duration is expressed in microseconds, and defaults to 10000000 (10 seconds). To ensure all the streams are interleaved correctly, libavformat will wait until it has at least one packet for each stream before actually writing any packets to the output file. When some streams are "sparse" (i.e. there are large gaps between successive packets), this can result in excessive buffering. This field specifies the maximum difference between the timestamps of the first and the last packet in the muxing queue, above which libavformat will output a packet regardless of whether it has queued a packet for all the streams. If set to 0, libavformat will continue buffering packets until it has a packet for each stream, regardless of the maximum timestamp difference between the buffered packets. **use**___**wallclock**___**as**___**timestamps** _integer_ **(**_input_**)** Use wallclock as timestamps if set to 1. Default is 0. **avoid**___**negative**___**ts** _integer_ **(**_output_**)** Possible values: **make**___**non**___**negative** Shift timestamps to make them non-negative. Also note that this affects only leading negative timestamps, and not non-monotonic negative timestamps. **make**___**zero** Shift timestamps so that the first timestamp is 0. **auto** **(default)** Enables shifting when required by the target format. **disabled** Disables shifting of timestamp. When shifting is enabled, all output timestamps are shifted by the same amount. Audio, video, and subtitles desynching and relative timestamp differences are preserved compared to how they would have been without shifting. **skip**___**initial**___**bytes** _integer_ **(**_input_**)** Set number of bytes to skip before reading header and frames if set to 1. Default is 0. **correct**___**ts**___**overflow** _integer_ **(**_input_**)** Correct single timestamp overflows if set to 1. Default is 1. **flush**___**packets** _integer_ **(**_output_**)** Flush the underlying I/O stream after each packet. Default is -1 (auto), which means that the underlying protocol will decide, 1 enables it, and has the effect of reducing the latency, 0 disables it and may increase IO throughput in some cases. **output**___**ts**___**offset** _offset_ **(**_output_**)** Set the output time offset. _offset_ must be a time duration specification, see **the** **Time** **duration** **section** **in** **the** [**ffmpeg-utils(1)](https://www.chedong.com/phpMan.php/man/ffmpeg-utils/1/markdown)** **manual**. The offset is added by the muxer to the output timestamps. Specifying a positive offset means that the corresponding streams are delayed bt the time duration specified in _offset_. Default value is 0 (meaning that no offset is applied). **format**___**whitelist** _list_ **(**_input_**)** "," separated list of allowed demuxers. By default all are allowed. **dump**___**separator** _string_ **(**_input_**)** Separator used to separate the fields printed on the command line about the Stream parameters. For example, to separate the fields with newlines and indentation: ffprobe -dump_separator " " -i ~/videos/matrixbench_mpeg2.mpg **max**___**streams** _integer_ **(**_input_**)** Specifies the maximum number of streams. This can be used to reject files that would require too many resources due to a large number of streams. **skip**___**estimate**___**duration**___**from**___**pts** _bool_ **(**_input_**)** Skip estimation of input duration when calculated using PTS. At present, applicable for MPEG-PS and MPEG-TS. **strict,** **f**___**strict** _integer_ **(**_input/output_**)** Specify how strictly to follow the standards. "f_strict" is deprecated and should be used only via the **ffmpeg** tool. Possible values: **very** strictly conform to an older more strict version of the spec or reference software **strict** strictly conform to all the things in the spec no matter what consequences **normal** **unofficial** allow unofficial extensions **experimental** allow non standardized experimental things, experimental (unfinished/work in progress/not well tested) decoders and encoders. Note: experimental decoders can pose a security risk, do not use this for decoding untrusted input. ### Format stream specifiers Format stream specifiers allow selection of one or more streams that match specific properties. The exact semantics of stream specifiers is defined by the "avformat_match_stream_specifier()" function declared in the _libavformat/avformat.h_ header and documented in the **Stream** **specifiers** **section** **in** **the** [**ffmpeg(1)](https://www.chedong.com/phpMan.php/man/ffmpeg/1/markdown)** **manual**. ## DEMUXERS Demuxers are configured elements in FFmpeg that can read the multimedia streams from a particular type of file. When you configure your FFmpeg build, all the supported demuxers are enabled by default. You can list all available ones using the configure option "--list-demuxers". You can disable all the demuxers using the configure option "--disable-demuxers", and selectively enable a single demuxer with the option "--enable-demuxer=_DEMUXER"_, or disable it with the option "--disable-demuxer=_DEMUXER"_. The option "-demuxers" of the ff* tools will display the list of enabled demuxers. Use "-formats" to view a combined list of enabled demuxers and muxers. The description of some of the currently available demuxers follows. **aa** Audible Format 2, 3, and 4 demuxer. This demuxer is used to demux Audible Format 2, 3, and 4 (.aa) files. ### apng Animated Portable Network Graphics demuxer. This demuxer is used to demux APNG files. All headers, but the PNG signature, up to (but not including) the first fcTL chunk are transmitted as extradata. Frames are then split as being all the chunks between two fcTL ones, or between the last fcTL and IEND chunks. ### -ignore Ignore the loop variable in the file if set. ### -max Maximum framerate in frames per second (0 for no limit). ### -default Default framerate in frames per second when none is specified in the file (0 meaning as fast as possible). ### asf Advanced Systems Format demuxer. This demuxer is used to demux ASF files and MMS network streams. ### -no Do not try to resynchronize by looking for a certain optional start code. ### concat Virtual concatenation script demuxer. This demuxer reads a list of files and other directives from a text file and demuxes them one after the other, as if all their packets had been muxed together. The timestamps in the files are adjusted so that the first file starts at 0 and each next file starts where the previous one finishes. Note that it is done globally and may cause gaps if all streams do not have exactly the same length. All files must have the same streams (same codecs, same time base, etc.). The duration of each file is used to adjust the timestamps of the next file: if the duration is incorrect (because it was computed using the bit-rate or because the file is truncated, for example), it can cause artifacts. The "duration" directive can be used to override the duration stored in each file. _Syntax_ The script is a text file in extended-ASCII, with one directive per line. Empty lines, leading spaces and lines starting with '#' are ignored. The following directive is recognized: ### "file path" Path to a file to read; special characters and spaces must be escaped with backslash or single quotes. All subsequent file-related directives apply to that file. ### "ffconcat version 1.0" Identify the script type and version. It also sets the **safe** option to 1 if it was -1. To make FFmpeg recognize the format automatically, this directive must appear exactly as is (no extra space or byte-order-mark) on the very first line of the script. ### "duration dur" Duration of the file. This information can be specified from the file; specifying it here may be more efficient or help if the information from the file is not available or accurate. If the duration is set for all files, then it is possible to seek in the whole concatenated video. ### "inpoint timestamp" In point of the file. When the demuxer opens the file it instantly seeks to the specified timestamp. Seeking is done so that all streams can be presented successfully at In point. This directive works best with intra frame codecs, because for non-intra frame ones you will usually get extra packets before the actual In point and the decoded content will most likely contain frames before In point too. For each file, packets before the file In point will have timestamps less than the calculated start timestamp of the file (negative in case of the first file), and the duration of the files (if not specified by the "duration" directive) will be reduced based on their specified In point. Because of potential packets before the specified In point, packet timestamps may overlap between two concatenated files. ### "outpoint timestamp" Out point of the file. When the demuxer reaches the specified decoding timestamp in any of the streams, it handles it as an end of file condition and skips the current and all the remaining packets from all streams. Out point is exclusive, which means that the demuxer will not output packets with a decoding timestamp greater or equal to Out point. This directive works best with intra frame codecs and formats where all streams are tightly interleaved. For non-intra frame codecs you will usually get additional packets with presentation timestamp after Out point therefore the decoded content will most likely contain frames after Out point too. If your streams are not tightly interleaved you may not get all the packets from all streams before Out point and you may only will be able to decode the earliest stream until Out point. The duration of the files (if not specified by the "duration" directive) will be reduced based on their specified Out point. **"file**___**packet**___**metadata** **key=value"** Metadata of the packets of the file. The specified metadata will be set for each file packet. You can specify this directive multiple times to add multiple metadata entries. ### "stream" Introduce a stream in the virtual file. All subsequent stream-related directives apply to the last introduced stream. Some streams properties must be set in order to allow identifying the matching streams in the subfiles. If no streams are defined in the script, the streams from the first file are copied. **"exact**___**stream**___**id** **id"** Set the id of the stream. If this directive is given, the string with the corresponding id in the subfiles will be used. This is especially useful for MPEG-PS (VOB) files, where the order of the streams is not reliable. _Options_ This demuxer accepts the following option: ### safe If set to 1, reject unsafe file paths. A file path is considered safe if it does not contain a protocol specification and is relative and all components only contain characters from the portable character set (letters, digits, period, underscore and hyphen) and have no period at the beginning of a component. If set to 0, any file name is accepted. The default is 1. -1 is equivalent to 1 if the format was automatically probed and 0 otherwise. **auto**___**convert** If set to 1, try to perform automatic conversions on packet data to make the streams concatenable. The default is 1. Currently, the only conversion is adding the h264_mp4toannexb bitstream filter to H.264 streams in MP4 format. This is necessary in particular if there are resolution changes. **segment**___**time**___**metadata** If set to 1, every packet will contain the _lavf.concat.start_time_ and the _lavf.concat.duration_ packet metadata values which are the start_time and the duration of the respective file segments in the concatenated output expressed in microseconds. The duration metadata is only set if it is known based on the concat file. The default is 0. _Examples_ • Use absolute filenames and include some comments: # my first filename file /mnt/share/file-1.wav # my second filename including whitespace file '/mnt/share/file 2.wav' # my third filename including whitespace plus single quote file '/mnt/share/file 3'\''.wav' • Allow for input format auto-probing, use safe filenames and set the duration of the first file: ffconcat version 1.0 file file-1.wav duration 20.0 file subdir/file-2.wav ### dash Dynamic Adaptive Streaming over HTTP demuxer. This demuxer presents all AVStreams found in the manifest. By setting the discard flags on AVStreams the caller can decide which streams to actually receive. Each stream mirrors the "id" and "bandwidth" properties from the "" as metadata keys named "id" and "variant_bitrate" respectively. **flv,** **live**___**flv** Adobe Flash Video Format demuxer. This demuxer is used to demux FLV files and RTMP network streams. In case of live network streams, if you force format, you may use live_flv option instead of flv to survive timestamp discontinuities. ffmpeg -f flv -i myfile.flv ... ffmpeg -f live_flv -i rtmp:///anything/key .... ### -flv Allocate the streams according to the onMetaData array content. ### -flv Ignore the size of previous tag value. ### -flv Output all context of the onMetadata. ### gif Animated GIF demuxer. It accepts the following options: **min**___**delay** Set the minimum valid delay between frames in hundredths of seconds. Range is 0 to 6000. Default value is 2. **max**___**gif**___**delay** Set the maximum valid delay between frames in hundredth of seconds. Range is 0 to 65535. Default value is 65535 (nearly eleven minutes), the maximum value allowed by the specification. **default**___**delay** Set the default delay between frames in hundredths of seconds. Range is 0 to 6000. Default value is 10. **ignore**___**loop** GIF files can contain information to loop a certain number of times (or infinitely). If **ignore**___**loop** is set to 1, then the loop setting from the input will be ignored and looping will not occur. If set to 0, then looping will occur and will cycle the number of times according to the GIF. Default value is 1. For example, with the overlay filter, place an infinitely looping GIF over another video: ffmpeg -i input.mp4 -ignore_loop 0 -i input.gif -filter_complex overlay=shortest=1 out.mkv Note that in the above example the shortest option for overlay filter is used to end the output video at the length of the shortest input file, which in this case is _input.mp4_ as the GIF in this example loops infinitely. ### hls HLS demuxer Apple HTTP Live Streaming demuxer. This demuxer presents all AVStreams from all variant streams. The id field is set to the bitrate variant index number. By setting the discard flags on AVStreams (by pressing 'a' or 'v' in ffplay), the caller can decide which variant streams to actually receive. The total bitrate of the variant that the stream belongs to is available in a metadata key named "variant_bitrate". It accepts the following options: **live**___**start**___**index** segment index to start live streams at (negative values are from the end). **allowed**___**extensions** ',' separated list of file extensions that hls is allowed to access. **max**___**reload** Maximum number of times a insufficient list is attempted to be reloaded. Default value is 1000. **m3u8**___**hold**___**counters** The maximum number of times to load m3u8 when it refreshes without new segments. Default value is 1000. **http**___**persistent** Use persistent HTTP connections. Applicable only for HTTP streams. Enabled by default. **http**___**multiple** Use multiple HTTP connections for downloading HTTP segments. Enabled by default for HTTP/1.1 servers. **http**___**seekable** Use HTTP partial requests for downloading HTTP segments. 0 = disable, 1 = enable, -1 = auto, Default is auto. ### image2 Image file demuxer. This demuxer reads from a list of image files specified by a pattern. The syntax and meaning of the pattern is specified by the option _pattern_type_. The pattern may contain a suffix which is used to automatically determine the format of the images contained in the files. The size, the pixel format, and the format of each image must be the same for all the files in the sequence. This demuxer accepts the following options: ### framerate Set the frame rate for the video stream. It defaults to 25. ### loop If set to 1, loop over the input. Default value is 0. **pattern**___**type** Select the pattern type used to interpret the provided filename. _pattern_type_ accepts one of the following values. **none** Disable pattern matching, therefore the video will only contain the specified image. You should use this option if you do not want to create sequences from multiple images and your filenames may contain special pattern characters. **sequence** Select a sequence pattern type, used to specify a sequence of files indexed by sequential numbers. A sequence pattern may contain the string "%d" or "%0_N_d", which specifies the position of the characters representing a sequential number in each filename matched by the pattern. If the form "%d0_N_d" is used, the string representing the number in each filename is 0-padded and _N_ is the total number of 0-padded digits representing the number. The literal character '%' can be specified in the pattern with the string "%%". If the sequence pattern contains "%d" or "%0_N_d", the first filename of the file list specified by the pattern must contain a number inclusively contained between _start_number_ and _start_number_+_start_number_range_-1, and all the following numbers must be sequential. For example the pattern "img-%03d.bmp" will match a sequence of filenames of the form _img-001.bmp_, _img-002.bmp_, ..., _img-010.bmp_, etc.; the pattern "i%%m%%g-%d.jpg" will match a sequence of filenames of the form _i%m%g-1.jpg_, _i%m%g-2.jpg_, ..., _i%m%g-10.jpg_, etc. Note that the pattern must not necessarily contain "%d" or "%0_N_d", for example to convert a single image file _img.jpeg_ you can employ the command: ffmpeg -i img.jpeg img.png **glob** Select a glob wildcard pattern type. The pattern is interpreted like a "glob()" pattern. This is only selectable if libavformat was compiled with globbing support. **glob**___**sequence** _(deprecated,_ _will_ _be_ _removed)_ Select a mixed glob wildcard/sequence pattern. If your version of libavformat was compiled with globbing support, and the provided pattern contains at least one glob meta character among "%*?[]{}" that is preceded by an unescaped "%", the pattern is interpreted like a "glob()" pattern, otherwise it is interpreted like a sequence pattern. All glob special characters "%*?[]{}" must be prefixed with "%". To escape a literal "%" you shall use "%%". For example the pattern "foo-%*.jpeg" will match all the filenames prefixed by "foo-" and terminating with ".jpeg", and "foo-%?%?%?.jpeg" will match all the filenames prefixed with "foo-", followed by a sequence of three characters, and terminating with ".jpeg". This pattern type is deprecated in favor of _glob_ and _sequence_. Default value is _glob_sequence_. **pixel**___**format** Set the pixel format of the images to read. If not specified the pixel format is guessed from the first image file in the sequence. **start**___**number** Set the index of the file matched by the image file pattern to start to read from. Default value is 0. **start**___**number**___**range** Set the index interval range to check when looking for the first image file in the sequence, starting from _start_number_. Default value is 5. **ts**___**from**___**file** If set to 1, will set frame timestamp to modification time of image file. Note that monotonity of timestamps is not provided: images go in the same order as without this option. Default value is 0. If set to 2, will set frame timestamp to the modification time of the image file in nanosecond precision. **video**___**size** Set the video size of the images to read. If not specified the video size is guessed from the first image file in the sequence. **export**___**path**___**metadata** If set to 1, will add two extra fields to the metadata found in input, making them also available for other filters (see _drawtext_ filter for examples). Default value is 0. The extra fields are described below: **lavf.image2dec.source**___**path** Corresponds to the full path to the input file being read. **lavf.image2dec.source**___**basename** Corresponds to the name of the file being read. _Examples_ • Use **ffmpeg** for creating a video from the images in the file sequence _img-001.jpeg_, _img-002.jpeg_, ..., assuming an input frame rate of 10 frames per second: ffmpeg -framerate 10 -i 'img-%03d.jpeg' out.mkv • As above, but start by reading from a file with index 100 in the sequence: ffmpeg -framerate 10 -start_number 100 -i 'img-%03d.jpeg' out.mkv • Read images matching the "*.png" glob pattern , that is all the files terminating with the ".png" suffix: ffmpeg -framerate 10 -pattern_type glob -i "*.png" out.mkv ### libgme The Game Music Emu library is a collection of video game music file emulators. See <****> for more information. It accepts the following options: **track**___**index** Set the index of which track to demux. The demuxer can only export one track. Track indexes start at 0. Default is to pick the first track. Number of tracks is exported as _tracks_ metadata entry. **sample**___**rate** Set the sampling rate of the exported track. Range is 1000 to 999999. Default is 44100. ### max___size _(bytes) The demuxer buffers the entire file into memory. Adjust this value to set the maximum buffer size, which in turn, acts as a ceiling for the size of files that can be read. Default is 50 MiB. ### libmodplug ModPlug based module demuxer See <****> It will export one 2-channel 16-bit 44.1 kHz audio stream. Optionally, a "pal8" 16-color video stream can be exported with or without printed metadata. It accepts the following options: **noise**___**reduction** Apply a simple low-pass filter. Can be 1 (on) or 0 (off). Default is 0. **reverb**___**depth** Set amount of reverb. Range 0-100. Default is 0. **reverb**___**delay** Set delay in ms, clamped to 40-250 ms. Default is 0. **bass**___**amount** Apply bass expansion a.k.a. XBass or megabass. Range is 0 (quiet) to 100 (loud). Default is 0. **bass**___**range** Set cutoff i.e. upper-bound for bass frequencies. Range is 10-100 Hz. Default is 0. **surround**___**depth** Apply a Dolby Pro-Logic surround effect. Range is 0 (quiet) to 100 (heavy). Default is 0. **surround**___**delay** Set surround delay in ms, clamped to 5-40 ms. Default is 0. **max**___**size** The demuxer buffers the entire file into memory. Adjust this value to set the maximum buffer size, which in turn, acts as a ceiling for the size of files that can be read. Range is 0 to 100 MiB. 0 removes buffer size limit (not recommended). Default is 5 MiB. **video**___**stream**___**expr** String which is evaluated using the eval API to assign colors to the generated video stream. Variables which can be used are "x", "y", "w", "h", "t", "speed", "tempo", "order", "pattern" and "row". **video**___**stream** Generate video stream. Can be 1 (on) or 0 (off). Default is 0. **video**___**stream**___**w** Set video frame width in 'chars' where one char indicates 8 pixels. Range is 20-512. Default is 30. **video**___**stream**___**h** Set video frame height in 'chars' where one char indicates 8 pixels. Range is 20-512. Default is 30. **video**___**stream**___**ptxt** Print metadata on video stream. Includes "speed", "tempo", "order", "pattern", "row" and "ts" (time in ms). Can be 1 (on) or 0 (off). Default is 1. ### libopenmpt libopenmpt based module demuxer See <****> for more information. Some files have multiple subsongs (tracks) this can be set with the **subsong** option. It accepts the following options: ### subsong Set the subsong index. This can be either 'all', 'auto', or the index of the subsong. Subsong indexes start at 0. The default is 'auto'. The default value is to let libopenmpt choose. ### layout Set the channel layout. Valid values are 1, 2, and 4 channel layouts. The default value is STEREO. **sample**___**rate** Set the sample rate for libopenmpt to output. Range is from 1000 to INT_MAX. The value default is 48000. ### mov/mp4/3gp Demuxer for Quicktime File Format & ISO/IEC Base Media File Format (ISO/IEC 14496-12 or MPEG-4 Part 12, ISO/IEC 15444-12 or JPEG 2000 Part 12). Registered extensions: mov, mp4, m4a, 3gp, 3g2, mj2, psp, m4b, ism, ismv, isma, f4v _Options_ This demuxer accepts the following options: **enable**___**drefs** Enable loading of external tracks, disabled by default. Enabling this can theoretically leak information in some use cases. **use**___**absolute**___**path** Allows loading of external tracks via absolute paths, disabled by default. Enabling this poses a security risk. It should only be enabled if the source is known to be non- malicious. **seek**___**streams**___**individually** When seeking, identify the closest point in each stream individually and demux packets in that stream from identified point. This can lead to a different sequence of packets compared to demuxing linearly from the beginning. Default is true. **ignore**___**editlist** Ignore any edit list atoms. The demuxer, by default, modifies the stream index to reflect the timeline described by the edit list. Default is false. **advanced**___**editlist** Modify the stream index to reflect the timeline described by the edit list. "ignore_editlist" must be set to false for this option to be effective. If both "ignore_editlist" and this option are set to false, then only the start of the stream index is modified to reflect initial dwell time or starting timestamp described by the edit list. Default is true. **ignore**___**chapters** Don't parse chapters. This includes GoPro 'HiLight' tags/moments. Note that chapters are only parsed when input is seekable. Default is false. **use**___**mfra**___**for** For seekable fragmented input, set fragment's starting timestamp from media fragment random access box, if present. Following options are available: **auto** Auto-detect whether to set mfra timestamps as PTS or DTS _(default)_ **dts** Set mfra timestamps as DTS **pts** Set mfra timestamps as PTS **0** Don't use mfra box to set timestamps **export**___**all** Export unrecognized boxes within the _udta_ box as metadata entries. The first four characters of the box type are set as the key. Default is false. **export**___**xmp** Export entire contents of _XMP__ box and _uuid_ box as a string with key "xmp". Note that if "export_all" is set and this option isn't, the contents of _XMP__ box are still exported but with key "XMP_". Default is false. **activation**___**bytes** 4-byte key required to decrypt Audible AAX and AAX+ files. See Audible AAX subsection below. **audible**___**fixed**___**key** Fixed key used for handling Audible AAX/AAX+ files. It has been pre-set so should not be necessary to specify. **decryption**___**key** 16-byte key, in hex, to decrypt files encrypted using ISO Common Encryption (CENC/AES-128 CTR; ISO/IEC 23001-7). _Audible_ _AAX_ Audible AAX files are encrypted M4B files, and they can be decrypted by specifying a 4 byte activation secret. ffmpeg -activation_bytes 1CEB00DA -i test.aax -vn -c:a copy output.mp4 ### mpegts MPEG-2 transport stream demuxer. This demuxer accepts the following options: **resync**___**size** Set size limit for looking up a new synchronization. Default value is 65536. **skip**___**unknown**___**pmt** Skip PMTs for programs not defined in the PAT. Default value is 0. **fix**___**teletext**___**pts** Override teletext packet PTS and DTS values with the timestamps calculated from the PCR of the first program which the teletext stream is part of and is not discarded. Default value is 1, set this option to 0 if you want your teletext packet PTS and DTS values untouched. **ts**___**packetsize** Output option carrying the raw packet size in bytes. Show the detected raw packet size, cannot be set by the user. **scan**___**all**___**pmts** Scan and combine all PMTs. The value is an integer with value from -1 to 1 (-1 means automatic setting, 1 means enabled, 0 means disabled). Default value is -1. **merge**___**pmt**___**versions** Re-use existing streams when a PMT's version is updated and elementary streams move to different PIDs. Default value is 0. ### mpjpeg MJPEG encapsulated in multi-part MIME demuxer. This demuxer allows reading of MJPEG, where each frame is represented as a part of multipart/x-mixed-replace stream. **strict**___**mime**___**boundary** Default implementation applies a relaxed standard to multi-part MIME boundary detection, to prevent regression with numerous existing endpoints not generating a proper MIME MJPEG stream. Turning this option on by setting it to 1 will result in a stricter check of the boundary value. ### rawvideo Raw video demuxer. This demuxer allows one to read raw video data. Since there is no header specifying the assumed video parameters, the user must specify them in order to be able to decode the data correctly. This demuxer accepts the following options: ### framerate Set input video frame rate. Default value is 25. **pixel**___**format** Set the input video pixel format. Default value is "yuv420p". **video**___**size** Set the input video size. This value must be specified explicitly. For example to read a rawvideo file _input.raw_ with **ffplay**, assuming a pixel format of "rgb24", a video size of "320x240", and a frame rate of 10 images per second, use the command: ffplay -f rawvideo -pixel_format rgb24 -video_size 320x240 -framerate 10 input.raw ### sbg SBaGen script demuxer. This demuxer reads the script language used by SBaGen <****> to generate binaural beats sessions. A SBG script looks like that: -SE a: 300-2.5/3 440+4.5/0 b: 300-2.5/0 440+4.5/3 off: - NOW == a +0:07:00 == b +0:14:00 == a +0:21:00 == b +0:30:00 off A SBG script can mix absolute and relative timestamps. If the script uses either only absolute timestamps (including the script start time) or only relative ones, then its layout is fixed, and the conversion is straightforward. On the other hand, if the script mixes both kind of timestamps, then the _NOW_ reference for relative timestamps will be taken from the current time of day at the time the script is read, and the script layout will be frozen according to that reference. That means that if the script is directly played, the actual times will match the absolute timestamps up to the sound controller's clock accuracy, but if the user somehow pauses the playback or seeks, all times will be shifted accordingly. ### tedcaptions JSON captions used for <****>. TED does not provide links to the captions, but they can be guessed from the page. The file _tools/bookmarklets.html_ from the FFmpeg source tree contains a bookmarklet to expose them. This demuxer accepts the following option: **start**___**time** Set the start time of the TED talk, in milliseconds. The default is 15000 (15s). It is used to sync the captions with the downloadable videos, because they include a 15s intro. Example: convert the captions to a format most players understand: ffmpeg -i talk1-en.srt ### vapoursynth Vapoursynth wrapper. Due to security concerns, Vapoursynth scripts will not be autodetected so the input format has to be forced. For ff* CLI tools, add "-f vapoursynth" before the input "-i yourscript.vpy". This demuxer accepts the following option: **max**___**script**___**size** The demuxer buffers the entire script into memory. Adjust this value to set the maximum buffer size, which in turn, acts as a ceiling for the size of scripts that can be read. Default is 1 MiB. ## METADATA FFmpeg is able to dump metadata from media files into a simple UTF-8-encoded INI-like text file and then load it back using the metadata muxer/demuxer. The file format is as follows: 1. A file consists of a header and a number of metadata tags divided into sections, each on its own line. 2. The header is a **;FFMETADATA** string, followed by a version number (now 1). 3. Metadata tags are of the form **key=value** 4. Immediately after header follows global metadata 5. After global metadata there may be sections with per-stream/per-chapter metadata. 6. A section starts with the section name in uppercase (i.e. STREAM or CHAPTER) in brackets (**[**, **]**) and ends with next section or end of file. 7. At the beginning of a chapter section there may be an optional timebase to be used for start/end values. It must be in form **TIMEBASE=**_num_**/**_den_, where _num_ and _den_ are integers. If the timebase is missing then start/end times are assumed to be in nanoseconds. Next a chapter section must contain chapter start and end times in form **START=**_num_, **END=**_num_, where _num_ is a positive integer. 8. Empty lines and lines starting with **;** or **#** are ignored. 9. Metadata keys or values containing special characters (**=**, **;**, **#**, **\** and a newline) must be escaped with a backslash **\**. 10. Note that whitespace in metadata (e.g. **foo** **=** **bar**) is considered to be a part of the tag (in the example above key is **foo** , value is **bar**). A ffmetadata file might look like this: ;FFMETADATA1 title=bike\\shed ;this is a comment artist=FFmpeg troll team [CHAPTER] TIMEBASE=1/1000 START=0 #chapter ends at 0:01:00 END=60000 title=chapter \#1 [STREAM] title=multi\ line By using the ffmetadata muxer and demuxer it is possible to extract metadata from an input file to an ffmetadata file, and then transcode the file into an output file with the edited ffmetadata file. Extracting an ffmetadata file with _ffmpeg_ goes as follows: ffmpeg -i INPUT -f ffmetadata FFMETADATAFILE Reinserting edited metadata information from the FFMETADATAFILE file can be done as: ffmpeg -i INPUT -i FFMETADATAFILE -map_metadata 1 -codec copy OUTPUT ## PROTOCOL OPTIONS The libavformat library provides some generic global options, which can be set on all the protocols. In addition each protocol may support so-called private options, which are specific for that component. Options may be set by specifying -_option_ _value_ in the FFmpeg tools, or by setting the value explicitly in the "AVFormatContext" options or using the _libavutil/opt.h_ API for programmatic use. The list of supported options follows: **protocol**___**whitelist** _list_ **(**_input_**)** Set a ","-separated list of allowed protocols. "ALL" matches all protocols. Protocols prefixed by "-" are disabled. All protocols are allowed by default but protocols used by an another protocol (nested protocols) are restricted to a per protocol subset. ## PROTOCOLS Protocols are configured elements in FFmpeg that enable access to resources that require specific protocols. When you configure your FFmpeg build, all the supported protocols are enabled by default. You can list all available ones using the configure option "--list-protocols". You can disable all the protocols using the configure option "--disable-protocols", and selectively enable a protocol using the option "--enable-protocol=_PROTOCOL_", or you can disable a particular protocol using the option "--disable-protocol=_PROTOCOL_". The option "-protocols" of the ff* tools will display the list of supported protocols. All protocols accept the following options: **rw**___**timeout** Maximum time to wait for (network) read/write operations to complete, in microseconds. A description of the currently available protocols follows. ### amqp Advanced Message Queueing Protocol (AMQP) version 0-9-1 is a broker based publish-subscribe communication protocol. FFmpeg must be compiled with --enable-librabbitmq to support AMQP. A separate AMQP broker must also be run. An example open-source AMQP broker is RabbitMQ. After starting the broker, an FFmpeg client may stream data to the broker using the command: ffmpeg -re -i input -f mpegts amqp://[[user]:[password]@]hostname[:port][/vhost] Where hostname and port (default is 5672) is the address of the broker. The client may also set a user/password for authentication. The default for both fields is "guest". Name of virtual host on broker can be set with vhost. The default value is "/". Muliple subscribers may stream from the broker using the command: ffplay amqp://[[user]:[password]@]hostname[:port][/vhost] In RabbitMQ all data published to the broker flows through a specific exchange, and each subscribing client has an assigned queue/buffer. When a packet arrives at an exchange, it may be copied to a client's queue depending on the exchange and routing_key fields. The following options are supported: ### exchange Sets the exchange to use on the broker. RabbitMQ has several predefined exchanges: "amq.direct" is the default exchange, where the publisher and subscriber must have a matching routing_key; "amq.fanout" is the same as a broadcast operation (i.e. the data is forwarded to all queues on the fanout exchange independent of the routing_key); and "amq.topic" is similar to "amq.direct", but allows for more complex pattern matching (refer to the RabbitMQ documentation). **routing**___**key** Sets the routing key. The default value is "amqp". The routing key is used on the "amq.direct" and "amq.topic" exchanges to decide whether packets are written to the queue of a subscriber. **pkt**___**size** Maximum size of each packet sent/received to the broker. Default is 131072. Minimum is 4096 and max is any large value (representable by an int). When receiving packets, this sets an internal buffer size in FFmpeg. It should be equal to or greater than the size of the published packets to the broker. Otherwise the received message may be truncated causing decoding errors. **connection**___**timeout** The timeout in seconds during the initial connection to the broker. The default value is rw_timeout, or 5 seconds if rw_timeout is not set. **delivery**___**mode** _mode_ Sets the delivery mode of each message sent to broker. The following values are accepted: **persistent** Delivery mode set to "persistent" (2). This is the default value. Messages may be written to the broker's disk depending on its setup. **non-persistent** Delivery mode set to "non-persistent" (1). Messages will stay in broker's memory unless the broker is under memory pressure. ### async Asynchronous data filling wrapper for input stream. Fill data in a background thread, to decouple I/O operation from demux thread. async: async: async:cache: ### bluray Read BluRay playlist. The accepted options are: ### angle BluRay angle ### chapter Start chapter (1...N) ### playlist Playlist to read (BDMV/PLAYLIST/?????.mpls) Examples: Read longest playlist from BluRay mounted to /mnt/bluray: bluray:/mnt/bluray Read angle 2 of playlist 4 from BluRay mounted to /mnt/bluray, start from chapter 2: -playlist 4 -angle 2 -chapter 2 bluray:/mnt/bluray ### cache Caching wrapper for input stream. Cache the input stream to temporary file. It brings seeking capability to live streams. The accepted options are: **read**___**ahead**___**limit** Amount in bytes that may be read ahead when seeking isn't supported. Range is -1 to INT_MAX. -1 for unlimited. Default is 65536. URL Syntax is cache: ### concat Physical concatenation protocol. Read and seek from many resources in sequence as if they were a unique resource. A URL accepted by this protocol has the syntax: concat:||...| where _URL1_, _URL2_, ..., _URLN_ are the urls of the resource to be concatenated, each one possibly specifying a distinct protocol. For example to read a sequence of files _split1.mpeg_, _split2.mpeg_, _split3.mpeg_ with **ffplay** use the command: ffplay concat:split1.mpeg\|split2.mpeg\|split3.mpeg Note that you may need to escape the character "|" which is special for many shells. ### crypto AES-encrypted stream reading protocol. The accepted options are: **key** Set the AES decryption key binary block from given hexadecimal representation. **iv** Set the AES decryption initialization vector binary block from given hexadecimal representation. Accepted URL formats: crypto: crypto+ ### data Data in-line in the URI. See <****___**URI**___**scheme**>. For example, to convert a GIF file given inline with **ffmpeg**: ffmpeg -i "data:image/gif;base64,R0lGODdhCAAIAMIEAAAAAAAA//8AAP//AP///////////////ywAAAAACAAIAAADF0gEDLojDgdGiJdJqUX02iB4E8Q9jUMkADs=" smiley.png ### file File access protocol. Read from or write to a file. A file URL can have the form: file: where _filename_ is the path of the file to read. An URL that does not have a protocol prefix will be assumed to be a file URL. Depending on the build, an URL that looks like a Windows path with the drive letter at the beginning will also be assumed to be a file URL (usually not the case in builds for unix-like systems). For example to read from a file _input.mpeg_ with **ffmpeg** use the command: ffmpeg -i file:input.mpeg output.mpeg This protocol accepts the following options: ### truncate Truncate existing files on write, if set to 1. A value of 0 prevents truncating. Default value is 1. ### blocksize Set I/O operation maximum block size, in bytes. Default value is "INT_MAX", which results in not limiting the requested block size. Setting this value reasonably low improves user termination request reaction time, which is valuable for files on slow medium. ### follow If set to 1, the protocol will retry reading at the end of the file, allowing reading files that still are being written. In order for this to terminate, you either need to use the rw_timeout option, or use the interrupt callback (for API users). ### seekable Controls if seekability is advertised on the file. 0 means non-seekable, -1 means auto (seekable for normal files, non-seekable for named pipes). Many demuxers handle seekable and non-seekable resources differently, overriding this might speed up opening certain files at the cost of losing some features (e.g. accurate seeking). ### ftp FTP (File Transfer Protocol). Read from or write to remote resources using FTP protocol. Following syntax is required. ftp://[user[:password]@]server[:port]/path/to/remote/resource.mpeg This protocol accepts the following options. ### timeout Set timeout in microseconds of socket I/O operations used by the underlying low level operation. By default it is set to -1, which means that the timeout is not specified. ### ftp-user Set a user to be used for authenticating to the FTP server. This is overridden by the user in the FTP URL. ### ftp-password Set a password to be used for authenticating to the FTP server. This is overridden by the password in the FTP URL, or by **ftp-anonymous-password** if no user is set. ### ftp-anonymous-password Password used when login as anonymous user. Typically an e-mail address should be used. ### ftp-write-seekable Control seekability of connection during encoding. If set to 1 the resource is supposed to be seekable, if set to 0 it is assumed not to be seekable. Default value is 0. NOTE: Protocol can be used as output, but it is recommended to not do it, unless special care is taken (tests, customized server configuration etc.). Different FTP servers behave in different way during seek operation. ff* tools may produce incomplete content due to server limitations. ### gopher Gopher protocol. ### gophers Gophers protocol. The Gopher protocol with TLS encapsulation. ### hls Read Apple HTTP Live Streaming compliant segmented stream as a uniform one. The M3U8 playlists describing the segments can be remote HTTP resources or local files, accessed using the standard file protocol. The nested protocol is declared by specifying "+_proto_" after the hls URI scheme name, where _proto_ is either "file" or "http". hls+ hls+file://path/to/local/resource.m3u8 Using this protocol is discouraged - the hls demuxer should work just as well (if not, please report the issues) and is more complete. To use the hls demuxer instead, simply use the direct URLs to the m3u8 files. ### http HTTP (Hyper Text Transfer Protocol). This protocol accepts the following options: ### seekable Control seekability of connection. If set to 1 the resource is supposed to be seekable, if set to 0 it is assumed not to be seekable, if set to -1 it will try to autodetect if it is seekable. Default value is -1. **chunked**___**post** If set to 1 use chunked Transfer-Encoding for posts, default is 1. **content**___**type** Set a specific content type for the POST messages or for listen mode. **http**___**proxy** set HTTP proxy to tunnel through e.g. ### headers Set custom HTTP headers, can override built in default headers. The value must be a string encoding the headers. **multiple**___**requests** Use persistent connections if set to 1, default is 0. **post**___**data** Set custom HTTP post data. ### referer Set the Referer header. Include 'Referer: URL' header in HTTP request. **user**___**agent** Override the User-Agent header. If not specified the protocol will use a string describing the libavformat build. ("Lavf/") ### user-agent This is a deprecated option, you can use user_agent instead it. **reconnect**___**at**___**eof** If set then eof is treated like an error and causes reconnection, this is useful for live / endless streams. **reconnect**___**streamed** If set then even streamed/non seekable streams will be reconnected on errors. **reconnect**___**on**___**network**___**error** Reconnect automatically in case of TCP/TLS errors during connect. **reconnect**___**on**___**http**___**error** A comma separated list of HTTP status codes to reconnect on. The list can include specific status codes (e.g. '503') or the strings '4xx' / '5xx'. **reconnect**___**delay**___**max** Sets the maximum delay in seconds after which to give up reconnecting **mime**___**type** Export the MIME type. **http**___**version** Exports the HTTP response version number. Usually "1.0" or "1.1". **icy** If set to 1 request ICY (SHOUTcast) metadata from the server. If the server supports this, the metadata has to be retrieved by the application by reading the **icy**___**metadata**___**headers** and **icy**___**metadata**___**packet** options. The default is 1. **icy**___**metadata**___**headers** If the server supports ICY metadata, this contains the ICY-specific HTTP reply headers, separated by newline characters. **icy**___**metadata**___**packet** If the server supports ICY metadata, and **icy** was set to 1, this contains the last non- empty metadata packet sent by the server. It should be polled in regular intervals by applications interested in mid-stream metadata updates. ### cookies Set the cookies to be sent in future requests. The format of each cookie is the same as the value of a Set-Cookie HTTP response field. Multiple cookies can be delimited by a newline character. ### offset Set initial byte offset. **end**___**offset** Try to limit the request to bytes preceding this offset. ### method When used as a client option it sets the HTTP method for the request. When used as a server option it sets the HTTP method that is going to be expected from the client(s). If the expected and the received HTTP method do not match the client will be given a Bad Request response. When unset the HTTP method is not checked for now. This will be replaced by autodetection in the future. ### listen If set to 1 enables experimental HTTP server. This can be used to send data when used as an output option, or read data from a client with HTTP POST when used as an input option. If set to 2 enables experimental multi-client HTTP server. This is not yet implemented in ffmpeg.c and thus must not be used as a command line option. # Server side (sending): ffmpeg -i somefile.ogg -c copy -listen 1 -f ogg http://: # Client side (receiving): ffmpeg -i http://: -c copy somefile.ogg # Client can also be done with wget: wget http://: -O somefile.ogg # Server side (receiving): ffmpeg -listen 1 -i http://: -c copy somefile.ogg # Client side (sending): ffmpeg -i somefile.ogg -chunked_post 0 -c copy -f ogg http://: # Client can also be done with wget: wget --post-file=somefile.ogg http://: **send**___**expect**___**100** Send an Expect: 100-continue header for POST. If set to 1 it will send, if set to 0 it won't, if set to -1 it will try to send if it is applicable. Default value is -1. **auth**___**type** Set HTTP authentication type. No option for Digest, since this method requires getting nonce parameters from the server first and can't be used straight away like Basic. **none** Choose the HTTP authentication type automatically. This is the default. **basic** Choose the HTTP basic authentication. Basic authentication sends a Base64-encoded string that contains a user name and password for the client. Base64 is not a form of encryption and should be considered the same as sending the user name and password in clear text (Base64 is a reversible encoding). If a resource needs to be protected, strongly consider using an authentication scheme other than basic authentication. HTTPS/TLS should be used with basic authentication. Without these additional security enhancements, basic authentication should not be used to protect sensitive or valuable information. _HTTP_ _Cookies_ Some HTTP requests will be denied unless cookie values are passed in with the request. The **cookies** option allows these cookies to be specified. At the very least, each cookie must specify a value along with a path and domain. HTTP requests that match both the domain and path will automatically include the cookie value in the HTTP Cookie header field. Multiple cookies can be delimited by a newline. The required syntax to play a stream specifying a cookie is: ffplay -cookies "nlqptid=nltid=tsn; path=/; domain=somedomain.com;" ### Icecast Icecast protocol (stream to Icecast servers) This protocol accepts the following options: **ice**___**genre** Set the stream genre. **ice**___**name** Set the stream name. **ice**___**description** Set the stream description. **ice**___**url** Set the stream website URL. **ice**___**public** Set if the stream should be public. The default is 0 (not public). **user**___**agent** Override the User-Agent header. If not specified a string of the form "Lavf/" will be used. ### password Set the Icecast mountpoint password. **content**___**type** Set the stream content type. This must be set if it is different from audio/mpeg. **legacy**___**icecast** This enables support for Icecast versions < 2.4.0, that do not support the HTTP PUT method but the SOURCE method. **tls** Establish a TLS (HTTPS) connection to Icecast. icecast://[[:]@]:/ ### mmst MMS (Microsoft Media Server) protocol over TCP. ### mmsh MMS (Microsoft Media Server) protocol over HTTP. The required syntax is: mmsh://[:][/][/] ### md5 MD5 output protocol. Computes the MD5 hash of the data to be written, and on close writes this to the designated output or stdout if none is specified. It can be used to test muxers without writing an actual file. Some examples follow. # Write the MD5 hash of the encoded AVI file to the file output.avi.md5. ffmpeg -i input.flv -f avi -y md5:output.avi.md5 # Write the MD5 hash of the encoded AVI file to stdout. ffmpeg -i input.flv -f avi -y md5: Note that some formats (typically MOV) require the output protocol to be seekable, so they will fail with the MD5 output protocol. ### pipe UNIX pipe access protocol. Read and write from UNIX pipes. The accepted syntax is: pipe:[] _number_ is the number corresponding to the file descriptor of the pipe (e.g. 0 for stdin, 1 for stdout, 2 for stderr). If _number_ is not specified, by default the stdout file descriptor will be used for writing, stdin for reading. For example to read from stdin with **ffmpeg**: cat test.wav | ffmpeg -i pipe:0 # ...this is the same as... cat test.wav | ffmpeg -i pipe: For writing to stdout with **ffmpeg**: ffmpeg -i test.wav -f avi pipe:1 | cat > test.avi # ...this is the same as... ffmpeg -i test.wav -f avi pipe: | cat > test.avi This protocol accepts the following options: ### blocksize Set I/O operation maximum block size, in bytes. Default value is "INT_MAX", which results in not limiting the requested block size. Setting this value reasonably low improves user termination request reaction time, which is valuable if data transmission is slow. Note that some formats (typically MOV), require the output protocol to be seekable, so they will fail with the pipe output protocol. ### prompeg Pro-MPEG Code of Practice #3 Release 2 FEC protocol. The Pro-MPEG CoP#3 FEC is a 2D parity-check forward error correction mechanism for MPEG-2 Transport Streams sent over RTP. This protocol must be used in conjunction with the "rtp_mpegts" muxer and the "rtp" protocol. The required syntax is: -f rtp_mpegts -fec prompeg=